Single vision lenses

ABSTRACT

Optical lens element with a prescription zone, suitable for use in wraparound or protective type eyewear. The element may also include a peripheral vision zone, with no prismatic jump between the zones. Design methods for the prescription zone include temporally rotating a prescription section about a vertical axis through the optical center thereof, and/or decentring the optical axis of said prescription section relative to the geometric axis thereof, and providing partial surface correction for astigmatic and/or mean power errors. For prescription powers in the range −6.0 to +6.0 diopters with 0 to 3 cyl, the optical lens element may be designed such that its front surface can be mounted in a frame of constant curvature of at least 5.0 diopters, with its back surface providing good clearance from temples and eyelashes. Applications include ophthalmic sunglass lenses.

The present invention relates to sunglass lenses, in particular sunglasslenses with refractive power.

It is known in the prior art to manufacture non-corrective eyeglassessuch as sunglasses or protective eyeglasses having wrap-around segmentsdesigned to shield the eye from incident light, wind, and foreignobjects in the temporal vision field of the wearer.

Visible light and light in the UV region may enter the eye from anglesas high as 100° from the line of sight.

It has not been possible, however, in prior art sunglasses or protectiveeyeglasses, to provide spectacle lenses with refractive power. The radiiof curvature required to provide an ophthalmic lens defining aprescription zone is such that the spectacles would produce a bug-eyedappearance, which would be cosmetically unacceptable.

Whilst attempts have been made in the prior art to provide a wrap-aroundsun shield over otherwise generally standard prescription eyeglasses,such products are generally cosmetically unacceptable and suffer fromsignificant optical distortions.

It is accordingly an object of the present invention to overcome, or atleast alleviate, one or more of the difficulties and deficienciesrelated to the prior art.

Accordingly, in a first aspect, there is provided an optical lenselement including

a front and back surface capable of forming a prescription (Rx) zone;and

a peripheral temporal zone.

Applicants have discovered that it is possible to provide a sufficientarea of the lens to function as a prescription zone and yet still toprovide a lens which provides a shield in the area of the temples. Thisis achieved by having a peripheral temporal zone.

By the term “optical lens element” as used herein, we mean an optical orophthalmic lens, semi-finished lens or lens formed from a pair of lenswafers which may be utilised in the formation of an optical lensproduct.

The ophthalmic lens element may be a lens of negative or positiverefractive power. Where the ophthalmic lens element includes anophthalmic lens wafer, the peripheral temporal zone may be provided bythe front wafer.

The optical lens element according to the present invention may beadapted for mounting in a frame of the wrap-around or shield type.

The peripheral temporal zone may be at least in part of generally toricshape. The peripheral temporal zone may-be at least in part generallypiano.

The peripheral temporal zone may itself form an extension of theprescription zone or may be a non-prescription zone.

In an alternative or additional aspect, the peripheral temporal zone maybe modified to permit light control within the zone.

The lens element may be rotated temporally about a vertical axis throughthe optical centre thereof or the optical axis may be decentred relativeto the geometric axis, or the lens element may be both rotated anddecentred.

It will be understood that the peripheral temporal zone, for a typicalsunglass lens element of the wrap-around type, may for example extendfor approximately 10 to 25 mm.

In a further aspect of the present invention, there is provided anoptical lens element providing prescription (Rx) correction generally inthe range −6.0 D to +6.0 D with 0 to +3 cyl

wherein the front surface is capable of being mounted in a frame ofconstant design curve irrespective of the Rx, such frame curves being5.0 D and above; and

the back surface provides good clearance from temples or eye lashes.

The ophthalmic lens element may form part of a series of lens elements,e.g. of the type described in International Patent ApplicationPCTIEP97/00105, the entire disclosure of which is incorporated herein byreference.

Preferably the front surface is capable of being mounted in a frame ofconstant design curve of between 8.0 D and 9.0 D.

More preferably the front surface of the lens element has a high curveextending from nasal to temporal limits, but the vertical curve is 6.0 Dor below.

It will be understood that such vertical curves permit the finalprescription lenses, preferably edged lenses, to be adapted to the shapeof the wearer's face and so locate closely in a form of the wrap-aroundtype (so-called “toric” design).

Alternatively the optical lens elements may be adapted for mounting in aframe of the shield type. Accordingly in a still further aspect of thepresent invention there is provided a unitary optical lens including

a pair of optical lens elements, each lens element providingprescription (Rx) correction generally in the range −6.0 D to +6.0 Dwith 0 to +3 cyl

wherein the front surface is capable of being mounted in a frame ofconstant design curve irrespective of the Rx, such frame curves being5.0 D and above; and

the back surface provides good clearance from temples or eye lashes.

Accordingly in a particularly preferred embodiment the present inventionprovides a spectacle frame, or a unitary lens, including a pair ofoptical lens elements, which lens elements provide true Rx correction ina prescription (Rx) zone for a wearer up to 50° off axis, preferably 80°off axis, and terminating in a peripheral temporal zone, that providesclear perception of objects in the peripheral area of human vision andavoids prismatic jump from the prescription zone to the peripheraltemporal zone.

The optical lens element according to the present invention may, whenmounted, in a spectacle frame, be rotated temporally about a verticalaxis through the optical centre thereof.

Accordingly in a further aspect of the present invention, there isprovided an optical lens element adapted for mounting in a frame of thewrap-around or shield type, such that the lens element is rotatedtemporally about a vertical axis through the optical centre thereof, thelens element including

a front and back surface capable of forming a prescription (Rx) zone;and optionally

a peripheral temporal zone;

the front and/or back surface bearing a surface correction to at leastpartially adjust for errors including astigmatic and power errors.

In this embodiment, whilst the optical axis continues to intersect theline of sight of the wearer, a number of optical effects and errors arethus introduced as discussed below. However, by suitable selection ofthe combination of front and/or back surface, the optical errors may bereduced or eliminated.

Accordingly, in a still further aspect of the present invention there isprovided an optical lens element adapted for mounting in a frame of thewrap-around or shield type, the lens element including

a front and back surface capable of forming a prescription (Rx) zone;and optionally

a peripheral temporal zone wherein the optical axis is decentredrelative to the geometric axis of the lens element to provide forprismatic correction,

the front and/or back surface bearing a surface correction to at leastpartially adjust for errors including astigmatic and power errors.

Applicants have discovered that it is possible to produce an opticallens element, preferably a sunglass lens element, which includes aprescription (Rx) zone and which is decentred to provide a prismaticcorrection.

Preferably the front and/or back surface of the optical lens elementfurther includes a surface correction to at least partially adjust forprismatic errors introduced by lens tilt.

Illustrative optical effects and errors may be summarised as follows:

The effects are described by consideration of the effects seen by thewearer along the line of sight that intersects the optical axis of thelens element:

Astigmatic Error

There is an induced astigmatic error such that the astigmatism, a, isproportional to the power of the lens, P, and proportional to the squareof the rotation angle of the lens.

Power Errors

When the lens is used in a wrap-around form the mean through power ofthe lens changes. The mean power error, dP, is proportional to theastigmatic error, a, and proportional to a constant, k, that is relatedto the index of the lens. Hence in a minus Rx the mean power becomesmore negative and in a plus Rx the mean power becomes more positive.

Prismatic Effects

Due to the rotation of the lens and the oblique angle of the opticalaxis, lens prism is introduced.

Off-axis Prismatic Disparity

Off-axis prismatic disparity will result from unequal distortions in thetemporal and nasal fields, resulting in poor binocular vision.

Other important observations:

The lens element described may result in increased off-axis power andastigmatic errors due to the selection of a base (front) curve that isdesigned to fit standard wrap frames, rather than for best opticalperformance.

These errors may result in un-accommodatable power errors.

One or more of the following corrections may be introduced to reduce theerrors described:

Mean Power Error Correction

The front and/or back surface curvature may be adjusted to account forthe change in mean power resulting from rotation of the lens, the degreeof correction depending upon a balance of wearer tolerable on-axis powererror and reduction of un-accommodatable off-axis power errors.

Hence a full power correction for the introduced shift in through powerto correct on-axis errors may be applied or a partial correction whenoff-axis power error is considered.

Astigmatic Error Correction

The front and/or back surface may at least in part be toric in nature tocorrect for astigmatic error resulting from the lens rotation discussedearlier. The degree of correction may fully correct for the astigmatismintroduced due to rotation of the lens or may be partially correcteddepending upon the application. A partial correction may be applied toachieve a tolerable on-axis astigmatic error so as to reduce theoff-axis astigmatic errors.

Prismatic Correction

The optical centre may be shifted horizontally to compensate for prisminduced by the lens rotation. This may be achieved by applyingprescribed prism during surfacing or shifting of the lens element in ahorizontal direction.

Additional Considerations

These corrections include, but are not limited to, pantoscopic lenstilt, variation in lens frame types, cosmetic requirements and averagepupil-centre to lens distances depending on frame and lens form types.

Off-axis Prismatic Disparity

To correct for off-axis prismatic disparity the lens may include anaspheric surface on either the front or back surfaces, or both.

Aspherisation of Surfaces

Aspherisation of either the front or back surfaces may be utilised tocorrect for off-axis errors including errors introduced due to tiltand/or the selection of the base curves. Such off-axis error may includepower and astigmatic error and prismatic disparity.

It will be understood, however, that whilst it is relatively simple tocorrect for any particular optical error, it is necessary to balance thecorrection to achieve acceptable overall performance of the lens.

Illustrative error corrections which may be undertaken for a typicalrotation of approximately 20° about the vertical axis, for a range ofplus (+) and (−) tens elements of varying power, are given in thefollowing Table.

Eyeside Curve Corrections Sphere Rx Mean Power Vertical Horizontal PowerError Astig Error Meridian Meridian −3.00 D −0.33 D −0.42 D × 90° 0.12 D0.54 D flatter flatter −6.00 D −0.66 D −0.84 D × 90° 0.24 D 1.08 Dflatter flatter +3.00 D +0.33 D −0.42 D × 0°  0.12 D 0.54 D steepersteeper +6.00 D +0.66 D −0.84 D × 0°  0.24 D 1.08 D steeper steeper

It is to be noted that the eyeside surface power corrections givenassume that the above errors are fully corrected to recover the sphereRx specified at the optical centre. Lesser corrections may beundertaken, if required, to achieve acceptable overall performance ofthe lens.

Accordingly in a preferred aspect the optical lens element includes

a front and/or back surface having a surface curvature adjusted topartially compensate for central mean through power error; and

a second surface correction to at least partially balance off-axis andon-axis astigmatic errors.

In a still further preferred aspect, the second surface correction mayinclude a toric component on the front and/or back surface to at leastpartially correct for astigmatic error.

Lens correction included in the optical lens element of the presentinvention may be grouped as two types:

those corrections that result from the lens rotation about the opticalaxis, or astigmatic and power error correction,

and those corrections required by the wearer's prescription, orprescription correction.

The front surface may, in a preferred aspect, include a base curvatureappropriate for high base curve lenses, e.g. for wrap around use. Thenature of the front surface may mainly be dictated by cosmeticrequirements.

Desirably, the front and/or back surface(s) of the optical lens elementincludes a spherical or toric component to provide the desiredprescription (Rx) in the prescription zone.

More preferably the front and/or back surface includes a toric componentand bears a surface correction to at least partially adjust for on-axisastigmatic and mean power errors. Such on-axis errors may result fromthe temporal rotation of the lens when mounted in a wrap-around orshield type frame.

Alternatively, or in addition, the front and/or back surface includes anaspheric component selected to at least partially adjust for off-axisastigmatic and mean power errors as well as prismatic disparity.

Preferably the front surface includes such an aspheric component. Suchoff-axis errors may result in part from the temporal rotation of thelens when mounted in a wrap-around or shield type frame and in part fromthe selection of a base curvature appropriate for high base curvelenses.

In a further preferred aspect, in order to provide the peripheraltemporal zone the front and/or back surface, preferably the frontsurface, is an aspheric surface that includes appropriate asphericcoefficients to define a peripheral temporal zone.

Alternatively, the peripheral temporal zone may be provided by having anextension of the curvature of the front and/or back surface, theopposite surface being modified to complement the extended surface.

Accordingly the optical tens element includes

a front surface including a spherical or toric component designed toprovide the desired prescription (Rx) in the prescription zone, andbearing a surface correction to at least partially adjust for errorsincluding astigmatic and mean power errors, in combination with the backsurface,

and including appropriate co-efficients to define a peripheral temporalzone; and a transition section therebetween designed to smoothly blendthe prescription zone and peripheral temporal zone

a back surface modified to complement the front surface.

Preferably the front surface in the peripheral temporal zone isgenerally spherical. More preferably the back surface is also generallyspherical and of equal curvature to the peripheral temporal zone, thusproviding a generally piano extension.

The back surface may preferably include a base curvature such that thepatient's required prescription power, Rx, is achieved. The back surfacemay be further modified to complement the front surface selected.

The back surface of the ophthalmic lens element according to the presentinvention may accordingly, in a preferred aspect, include a toricsurface selected to achieve the prescribed optical power and theprescribed lens cylinder correction.

In a preferred aspect, the toric back surface may further include asurface correction to compensate for mean power and astigmatic errorsintroduced by lens wrap.

In a still further preferred aspect, the toric surface may be anaspheric surface. The aspheric toric surface may include an adjustmentto correct off-axis astigmatic and/or mean power errors.

Accordingly, in a preferred aspect the optical lens element includes

a spherical front surface that includes a base curvature appropriate forhigh base curve lenses, and

a toric back surface of appropriate curvature to provide the prescribedoptical lens power and prescribed lens cylinder requirement andincluding an adjustment for astigmatic and mean power errors tocompensate for lens wrap.

In an alternative embodiment, the optical lens element includes

a toric front surface that includes a base curvature appropriate forhigh base curve lenses, and a toric adjustment for astigmatic errorcorrection to compensate for lens wrap, and

a toric back surface of appropriate curvature to provide the prescribedoptical lens power and prescribed lens cylinder.

In a further alternative embodiment, the optical lens element includes

an aspheric front surface that includes a base curvature appropriate forhigh base curve lenses and appropriate aspheric coefficients to correctfor off-axis power and/or astigmatism errors; and

a toric back surface of appropriate curvature to provide the prescribedoptical lens power and prescribed lens cylinder requirement thatincludes adjustments for astigmatic error correction to compensate forlens wrap.

In a still further alternative embodiment, the optical lens elementincludes

an aspheric toric front surface that includes a base curvatureappropriate for high base curve lenses, and a toric adjustment forastigmatic error correction to compensate for lens wrap, and

a toric back surface of appropriate curvature to provide the prescribedoptical lens power and prescribed lens cylinder.

The asphericity on the front surface may function to provide appropriateaspheric coefficients to correct for off-axis power and/or astigmaticerrors.

The optical lens element accordingly may include

a spherical front surface that includes a base curvature appropriate forhigh base curve lenses, and

an aspheric toric back surface with appropriate aspheric coefficients tocorrect for off-axis power and/or astigmatism errors and a toricadjustment for astigmatic and mean power error correction to compensatefor lens wrap, prescribed optical lens power and prescribed lenscylinder.

Alternatively the optical lens element includes

a toric front surface that includes a base curvature appropriate forhigh base curve lenses, and a toric adjustment for astigmatic and meanpower error correction to compensate for lens wrap, and

an aspheric toric back surface which includes appropriate asphericcoefficients to correct for off-axis power and astigmatism errors,prescribed optical lens power and prescribed lens cylinder.

In a further alternative embodiment, the optical lens element includes

an aspheric front surface that includes a base curvature appropriate forhigh base curve lenses and appropriate aspheric coefficients to correctfor off-axis power and/or astigmatism errors, and

an aspheric toric back surface with appropriate aspheric coefficients tocorrect for off axis power and/or astigmatism errors and a toricadjustment for astigmatic error correction to compensate for lens wrap,prescribed optical lens power and prescribed lens cylinder.

In a still further alternative embodiment, the optical lens elementincludes

an aspheric toric front surface that includes a base curvatureappropriate for high base curve lenses, a toric adjustment forastigmatic error correction to compensate for lens wrap, and includesappropriate aspheric coefficients to correct for off-axis power and/orastigmatism errors, and

an aspheric toric back surface with appropriate aspheric coefficients tocorrect for astigmatic and mean power errors, prescribed optical lenspower and prescribed lens cylinder.

In a particularly preferred embodiment, the optical lens elementincludes

an aspheric front surface that includes a base curvature appropriate forhigh base curve lenses and appropriate aspheric coefficients to define aperipheral temporal zone; and

a back surface of appropriate curvature to provide the prescribedoptical lens power and prescribed lens cylinder and includingadjustments for astigmatic and mean power error correction to compensatefor lens wrap.

In this embodiment, the power, cylinder and error corrections may all beundertaken on the back surface, thus minimising the difficulties indesigning the wrap-around type front surface.

Preferably the aspheric front surface may exhibit line symmetry aboutthe horizontal geometric axis thereof. The aspheric front surface mayalternatively or in addition exhibit line symmetry about the verticalgeometric axis thereof. Such line symmetry further simplifies the designof the front lens surface whilst improving the aesthetic appearancethereof.

Preferably the aspheric surface includes a correction in the horizontalsection. More preferably the back surface includes a base curvature suchthat patient's required prescription power, Rx, in the prescription zoneis achieved; the back surface being further modified to complement thefront surface selected.

The aspheric front surface may be of generally conic shape.

In a preferred aspect of the present invention the ophthalmic lenselement may be formed as a laminate of a back and front lens element.

Accordingly, in a preferred aspect of the present invention there isprovided a laminate optical article adapted for mounting in a frame ofthe wrap-around or shield type, including

a front lens element;

a complementary back lens element, the front and back surfaces of thelaminate optical article being capable of forming a prescription (Rx)zone;

the front and/or back surface bearing a correction to at least partiallyadjust for errors including astigmatic and mean power errors;

the front and/or back lens element optionally including

a peripheral temporal zone.

As discussed above, the laminate article may be rotated temporally abouta vertical axis through the optical centre thereof, or the optical axismay be decentred relative to the geometric axis, or the lens element maybe both rotated and decentred.

Accordingly, in a preferred embodiment of this aspect of the presentinvention there is provided a laminate optical article adapted formounting in a frame of the wrap-around or shield type, such that thelens element is rotated temporally about a vertical axis through theoptical centre thereof, including

a front lens element;

a complementary back lens element, the front and back surfaces of thelaminate optical article being capable of forming a prescription (Rx)zone; the front and/or back surface bearing a correction to at leastpartially adjust for errors including astigmatic errors;

the front and/or back lens element optionally including

a peripheral temporal zone.

In a preferred embodiment, the front lens element may be generallyplano.

The corresponding back lens element may include a lens element ofpositive or negative power.

If desired, there may be a distribution of distance power and cylinderbetween the front and back lens element.

Alternatively, the back lens element may be relatively thick, thelaminate optical article forming a semi-finished lens.

In an alternative or additional aspect, the lens element may be modifiedto permit light control within the peripheral temporal zone. Desirablythe peripheral temporal zone may be modified so that no images arecreated in temporal vision.

The peripheral temporal zone of the optical lens element according tothe present invention may be constructed to maximise cosmeticappearance. Ideally, the peripheral temporal zone should show little orno optical difference from the remainder of the front surface of theophthalmic lens element. For example, where the prescription Rx surfaceof the ophthalmic lens is a minus Rx lens, the temporal extension mayexhibit a zero refractive power or positive refractive power. Thetemporal extension may be tapered in cross-section to maximise cosmeticacceptability.

Accordingly, in a preferred aspect the curvature of the front surface ismodified in the peripheral temporal zone to substantially correspond tothe curvature of the back surface thereof.

It will be understood that the peripheral temporal zone thus formed is asubstantially piano extension.

The peripheral temporal zone may be treated with any suitable coatingsto maximise the cosmetic appearance of the front surface thereof.

For example, the peripheral temporal zone may be designed such thatthere is a rapid transition from the interface between the temporal zoneand the surface of refractive power such that vision will be out offocus to the wearer within the temporal extension. For example, for aminus Rx lens, the minimum degree to which the nominal power of thetemporal segment should be positive relative to the distance Rx is inthe range of approximately 1 to 1.25 Dioptres.

It will be understood that for a minus Rx lens, it is possible for onlythe front surface of the lens to bear the temporal zone. The backsurface of the lens may be of conventional spherical or toric formwhilst the angular reach of the temporal extension increases as the basecurve of the lens is made steeper. For lenses where the base curve isrelatively modest, for example 4 or 6 Dioptres, the temporal reach maybe reduced compared to lenses of higher base curve. This is useful ifthe primary purpose of the lens design is to provide appealing cosmeticsby eliminating the conventional edge on a minus Rx lens.

In an alternative aspect, where the front surface of the ophthalmic lensforms a plus Rx lens, the peripheral temporal zone may vary from thepositive lens to approximately plano (for example a cylindrical lens).The ophthalmic lens of such construction may be suitable forprescriptions near piano if the temporal extension is likewise piano orslightly negative in refractive power. If the temporal extension retainssome positive power as for a high plus Rx lens, this power may be atleast 1 to 1.5 Dioptres less than the plus value of the Rx.

In a preferred embodiment, the front and rear surface of the opticallens element may together define a lens of minus power.

The front surface of the lens element in this embodiment may be ofgenerally circular cross-section.

The rear surface of the lens element may be of generally coniccross-section.

The front surface to be of generally conic cross-section in theperipheral temporal zone, thus providing a generally piano temporalcross-section.

As stated above, the lens element may be modified to permit lightcontrol within the peripheral temporal zone. The reflected colour of asunglass lens is primarily a function of the dyes at the front surfaceof the lens. A mirror coating may be applied to the back surface of thelens so that the combination of front and back surface reflectionsachieves specular intensity (mirror) and the sense of lens colour(tint). Alternatively, or in addition, a different tint coating or layermay be provided at the rear surface of the lens. This may alter both theintensity and spectral character of transmitted and reflected raysinteracting with the over-tinted region of the lens.

In a further option, the front or rear surface (preferably the rear) maybe frosted so that reflected and transmitted light is diffuse. That is,images are not formed by light which enters the lens. The frosted partof the lens is visually opaque (translucent) to a wearer. To someoneelse, the lens will reflect the tinted colour from its front surfaceagainst a dull shadow from the frosted part of the rear surface.Preferably the rear surface may include a localised mirror coating fromwhich the reflection is a matte finish.

The peripheral temporal zone may be treated in a number of ways so thatit will not create images in peripheral vision, irrespective of theoptical design. The most direct methods simply prevent a perceptibleintensity of focused light from passing through by blocking it with anyone or a combination of:

Back Surface Gradient Mirror

Back Surface Gradient (Black) Tint

Back Surface Mist

The mirror coating may be introduced utilising conventional techniques,for example vacuum deposition of metal film on a finished lens. Achemical solution of a pristine metallic layer may be deposited on partof a casting mould and subsequently a lens is cast against that mould. Ametal mirror thus formed may transmit insufficient light to form anytroublesome images and reflecting a soft matte finish in copper, nickelor whatever the chosen metal.

Alternatively, or in addition, the temporal extension may include one ormore of the following:

Reflection Holographic Film: mirrored polymer sheet, e.g. approximately0.5 mm thick giving brightly coloured, changing reflected colourpatterns

Light Control Film: for example polycarbonate film, e.g. 0.8 mm thicklimiting light transmission to a narrow angular band

Reflective Film: for example Mylar film 0.025 mm thick, 10%transmission/90% reflection

Liquid Crystal Film: for example polymeric sheet 0.20 mm thick changingcolour across the full spectrum with changing temperature.

The ophthalmic lens may be formulated from any suitable material. Apolymeric material may be used. The polymeric material may be of anysuitable type. The polymeric material may include a thermoplastic orthermoset material. A material of the diallyl glycol carbonate type maybe used.

The polymeric article may be formed from cross-linkable polymericcasting compositions, for example as described in applicants U.S. Pat.No. 4,912,155, U.S. patent application Ser. No. 07/781,392, AustralianPatent Applications 50581/93 and 50582/93, and European PatentSpecification 453159A2, the entire disclosures of which are incorporatedherein by reference.

Such cross-linkable polymeric casting compositions may include adiacrylate or dimethacrylate monomer (such as polyoxyalkylene glycoldiacrylate or dimethacrylate or a bisphenol fluorene diacrylate ordimethacrylate) and a polymerisable comonomer, e.g. methacrylates,acrylates, vinyls, vinyl ethers, allyls, aromatic olefins, ethers,polythiols and the like.

For example, in Australian Patent Application 81216/87, the entiredisclosure of which is incorporated herein by reference, applicantdescribes a cross-linkable coating composition including at leastpolyoxyalkylene glycol diacrylate or dimethacrylate and at least onepoly functional unsaturated cross-linking agent.

Further, in Australian Patent Application 75160/91, the entiredisclosure of which is incorporated herein by reference, applicantdescribes a polyoxyalkylene glycol diacrylate or dimethacrylate; amonomer including a recurring unit derived from at least oneradical-polymerisable bisphenol monomer capable of forming a homopolymerhaving a high refractive index of more than 1.55; and a urethane monomerhaving 2 to 6 terminal groups selected from a group comprising acrylicand methacrylic groups.

Such polymeric formulations are UV cured or cured by a combination of UVand thermal treatment. The range of optical lenses sold under the tradedesignations “Spectralite” by Applicants have been found to be suitable.

The polymeric material may include a dye, preferably a photochromic dye,which may, for example, be added to the monomer formulation used toproduce the polymeric material. The variation in depth of colour may beminimised by incorporating a pigment or dye into one or more layers ofthe optical article.

The ophthalmic lens element according to the present invention mayfurther include standard additional coatings to the front or backsurface including electrochromic coatings.

The front lens surface may include an anti-reflective (AR) coating, forexample of the type described in U.S. Pat. No. 5,704,692 to applicants,the entire disclosure of which is incorporated herein by reference.

The front lens surface may include an abrasion resistant coating. e.g.of the type described in U.S. Pat. No. 4,954,591 to applicants, theentire disclosure of which is incorporated herein by reference.

In a particularly preferred form, the laminate ophthalmic article mayinclude an inner layer providing desired optical properties of the typedescribed in International Patent Application PCT/AU96/00805 toapplicants, the entire disclosure of which is incorporated herein byreference.

The front and back surfaces may further include one or more additionsconventionally used in casting compositions such as inhibitors, dyesincluding thermochromic and photochromic dyes, e.g. as described above,polarising agents, UV stabilisers and materials capable of modifyingrefractive index.

In a further preferred aspect of the present invention the optical lenselement may be modified to accentuate facial form in the nasal region.

Accordingly the optical lens element may include a region of reduced oropposite curvature defining a nasal accentuating region.

In a more preferred form, the lens element may reach forward toward thenasal bridge and backward toward the temples.

In a still further aspect of the present invention there is providedspectacles including

a spectacle frame of the wrap-around type adapted to receive a pair ofoptical lenses such that each lens is rotated temporally about avertical axis through the optical centre thereof; and

a pair of optical lens elements, each lens element including

a front and/or back surface capable of forming a prescription (Rx)surface; and optionally

a peripheral temporal zone;

the front and/or back surface bearing a surface correction to at leastpartially adjust for errors including astigmatic errors.

The front and back surfaces of the optical lens elements may be of thetypes described above. The optical lens element may be decentred.

The spectacle frame according to this aspect of the present inventionmay be of any suitable type. The spectacle frame may permit adjustmentof the inter-pupillary distance for example via attachment of a lens tothe frame supports. Frames of the rimless and temple bar type may beused.

The ophthalmic lenses mounted within the frame may be formed from asemi-finished lens or front and back lens wafer as described above. Theophthalmic lenses may bear a prescription surface of minus or pluspower.

In a further aspect of the present invention, there is provided a methodof designing an optical lens element adapted for mounting in a frame ofthe wrap-around or shield type, which method includes

providing

a mathematical or numerical representation of a surface of ;an opticallens element including a section designed to provide the desiredprescription (Rx) in the prescription zone; and optionally addingthereto a mathematical or numerical representation of a peripheraltemporal zone to define a complete lens surface;

rotating and/or decentring the representation of the lens surface topermit mounting in a suitable frame; and

modifying the representation of the lens surface to at least partiallyadjust for errors including astigmatic and mean power errors.

In a preferred aspect, the method may include

providing a mathematical or numerical representation of an asphericfront surface of an optical lens element including a section designed toprovide the desired prescription (Rx) in the prescription zone andhaving appropriate aspheric coefficients to define a peripheral temporalzone;

rotating and/or decentring the representation of the lens surface topermit mounting in a suitable frame;

subsequently providing a mathematical or numerical representation of aprescription (Rx) back surface; and

modifying the representation of the back surface of the lens element toat least partially adjust for prismatic and/or astigmatic errors.

Preferably the method includes

providing

a mathematical or numerical representation of a surface of an opticallens element including a section designed to provide the desiredprescription (Rx) in the prescription zone; and adding thereto

a first mathematical or numerical representation of a peripheraltemporal zone thereto; and

a second mathematical or numerical representation of a transitionsection designed to smoothly blend the prescription section andperipheral temporal zone to define a complete lens surface;

rotating and/or decentring the representation of the lens surface topermit mounting in a suitable frame; and

modifying the representation of the lens surface to at least partiallyadjust for errors including astigmatic and mean power errors.

In a particularly preferred form the aspheric front surface is an atoricfront surface. The atoric front surface may exhibit line symmetry alongthe horizontal and/or vertical axis.

In a further preferred form the back surface is a toric back surface.

In a preferred form the aspheric front surface may include an additionalcorrection in the horizontal direction to adjust for errors due torotation.

Normal representation of the cross-section of a spherical or asphericlens surface may be via the coordinates

sag=A ₂ R ² +A ₄ R ⁴ +A ₆ R ⁶ +A ₈ R ⁸

where R is the radius measured from the optical axis and A₂, A₄, A₆ andA₈ are coefficients that define power and asphericity. It is assumedthat the lens is rotationally symmetric about the optical axis.

Thus

R ² =x ² +z ²

where the x axis is normal to the optical axis (y) in the directiontowards the temples and the z axis is vertical with respect to awearer's face.

The use of asphericity in conventional lens design is to produce smalldeviations from spherical form and the components of power are definedby the surface curvatures

T=[d ² y/dr ²]/[1+(dy/dr)²]^(3/2) tangential

S=(dy/dr)/r[1+(dy/dr)²]^(1/2) tangential

where the sag is denoted by y.

Surface power of the lens is therefore defined by the two derivatives

dy/dr=2A ₂ R+4A ₄ R ³+6A ₆R⁵+8A ₈ R ⁷,

and

d ² y/dr ²=2A ₂+12A ₄ R ²+30A ₆R⁴+56A ₈ R ⁸.

Torus Periphery

It is convenient to set up a torus geometry by regarding the total SAGas that due to the basic lens design curve plus a component “DSAG” whichcomes from a temporal curvature extending beyond some radius Ro andwhich is defined by a similar set of coefficients operating on theradial dimension (R−Ro). In this case

sag=SAG R≦Ro,

wherein R is the radius measured from the optical axis and A₂, A₄, A₆and A₈ are coefficients that define power and asphericity. It is assumedthat the lens is rotationally symmetric about the optical axis.

sag=SAG+DSAG R≧Ro,

wherein R₀ defines the periphery of the temporal region; and

DSAG=B ₂(R−Ro)² +B ₄(R−Ro)⁴ +B ₆(R−Ro)⁶ +B ₈(R−Ro)⁸

wherein B₂, B₄, B6 and B₈ are coefficients that define power andasphericity.

The first and second derivatives of sag are then the sums of theindividual derivatives

dy/dr→dy ₁ /dr)_(r=R) +dy ₂ /dr)_(r=R−R0),

d ² y/dr ² →d ² y ₁ /dr ²)_(r=R) +d ² y ₂ /dr ²)_(r=R−R0),

where by definition both y and dy/dr are continuous at R=Ro, but thesecond differential is discontinuous.

In this model, then, the sagittal surface curvature is continuous andthe tangential surface curvature is not unless the following conditionapplies

B ₂=0

Generalised Torus Formulation

If we generalise the expressions so that

sag=SAG+α(DSAG)^(N) for R>Ro,

where α and N≧1 are numerical parameters, we gain greater freedom tomodel the surface and gain better control over surface power changes atthe onset of toric curvature. The first and second derivatives arecontinuous at R=Ro if either of the following conditions applies

2>N≧1 and B₂=O,

or

N≧2 for all values of B₂.

Conveniently, we have found a generalised representation that providescontinuity of surface curvature in both sagittal and tangentialdirections. That is, we can model the toric form without discontinuitiesin surface power. Given such forms, we are able to place one surfacebehind another of similar generating equation to provide a lens withstrong curvatures but without discontinuities in refractive powerthrough the lens.

When the curves produced by the above models with N=1 and N=2 arecalculated and plotted, it is evident that the torus sheet blendsasymptotically to the central optic zone, provided the condition on B₂is observed. The model departs very gradually from the design sphere,blending the optics of the two design zones.

Further Generalisation of Torus Formulation

It will be understood that the surfaces of a lens element are surfacesof rotation swept by any of the expressions above for sag with respectto a chosen axis of revolution. In the mathematical development above,we have specified rotational symmetry about the optical axis. Thisgenerates a lens form with the same mean surface power at horizontal andvertical meridians, having a peripheral temporal zone around the entireperimeter of the lens element.

Before such a lens element can be mounted proximate the face in a wraparound frame or shield, the temporal extension is cut away except at thelocations corresponding to the temples of the wrap around eyewear.

In an alternative embodiment, the appropriate surface alteration may beformed from the SAG curves as defined above by rotating the sag curveabout an axis parallel to the x axis within the plane of the horizontalmeridian. The curved portions intended to provide the temporal extensionof such lenses are then located towards the ends of the horizontalmeridian, whilst the vertical curves may retain conventional sphericalor aspheric lens form.

The expression for the sag on the surface of a lens element formed inthis manner is${sag} = {{\sum\limits_{n = 1}^{4}{( {{A_{2n}x^{2n}} + {C_{2n}Z^{2n}}} )\quad {for}\quad x}} \leq x_{0}}$$\quad {{{\sum\limits_{n = 1}^{4}( {{A_{2n}x^{2n}} + {C_{2n}Z^{2n}}} )} + {\alpha \{ {\sum\limits_{n = 1}^{4}\quad {B_{2n}( {x - x_{0}} )}^{2n}} \}^{N}\quad {for}\quad x}} \geq x_{0}}$

If the parameters A_(2n) and C_(2n) are set equal, the optic zone hasthe same surface power in vertical and horizontal meridians.

If the parameters C_(2n) correspond to curves of lower power than theA_(2n) parameters specify, the surface power of the optic zone will belower in the vertical meridian. Lens elements formed in this way assistin achieving conformance of the wrap around eyewear to the face. A highbase curve of the order of B or 9 Dioptres way be used to wrap laterallyto the temples. However a lower curve, for example approximately 2 to 5Dioptres matches the vertical shape of the face and allows the lenses tobe placed closer to the eyes without indenting on the brows or cheeks.

The use of such more conventional base curves to define the verticalmeridian also alleviates the need to apply off axis astigmatism andpower corrections in this meridian.

The present invention will now be more fully described with reference tothe accompanying figures and examples. It should be understood, however,that the description following is illustrative only and should not betaken in any way as a restriction on the generality of the inventiondescribed above.

In the drawings:

FIG. 1 illustrates light paths through a lens surface bearing a sunglasstint.

FIG. 2 is a stylised illustration of an ophthalmic lens (right handlens) off minus Rx power.

FIG. 3 is a stylised illustration of the peripheral temporal zone of anophthalmic lens bearing a positive Rx surface.

FIG. 4 is a stylised side view of an ophthalmic lens bearing a minus Rxsurface according to the present invention.

FIG. 5 is a series of cross-sectional views of front surface laminatingwafers for piano, plus, and minus lenses according to the presentinvention. Each front surface is rotationally symmetric.

FIG. 6 is a stylised plus and minus back surface wafer for lamination tothe front surface wafers illustrated in FIG. 5. Cylinder correction maybe carried out on the back surfaces.

FIG. 7(a) is a semi-finished optical blank: finished optical surface(1), unfinished rear surface (1′), axis of rotation symmetry (3),desired optical axis (4). In this example, the blank diameter is 76 mm,the front surface curve is 8 Dioptres and the angle between the axes (3)and (4) is 20°. The thickness of the blank may be 15 mm or so, dependingon design needs.

FIG. 7(b) is a second optical surface (2) rotationally symmetric aboutthe optical axis (4) created on the front of the optical blank bygrinding and polishing. The difference in power of (1) and (2) is thefinal Rx power of the lens. In this example, (2) is 4 Dioptres.

FIG. 7(c) is a final Rx lens of power −4 Dioptres with a central opticalzone of width ±35° around the optical axis (4). Curve (5) is identicaldioptric power to (1) centred on axis (4). The temporal limit of thepiano skirt (upper part of the drawing) of this lens is 88° from theline of forward sight for a rear vertex distance of 28 mm.

FIG. 8(a) is a true piano lens of 9 Dioptre base curve. Curves (6) and(7) are both 9 Dioptres centred on the optical axis (4). Note theapparent “base-in” prism of the lens when considered in terms of thedisplaced geometric axis. The nasal (lower) part of the lens is thicker.

FIG. 8(b) is a final Rx lens of power −4 Dioptres created by curve (8)of 5 Dioptres centred on the optical axis (4).

FIG. 9(a) is a true piano lens of 10 Dioptre base curve. Curves (9) and(10) are both 10 Dioptres centred on the optical axis (4). Note theapparent “base-in” prism of the lens when considered in terms of thedisplaced geometric axis. The nasal (lower) part of the lens is thicker.

FIG. 9(b) is a final Rx lens of power −4 Dioptres created by curve (11)of 6 Dioptres centred on the optical axis (4). The optic zone width is±45° for a rear vertex distance of 28 mm, with the temporal limit of thepiano skirt of the lens being 95°.

FIG. 10(a) is a true piano lens of 12 Dioptre base curve. Curves (12)and (13) are both 12 Dioptres centred on the optical axis (4). Note theapparent “base-in” prism of the lens when considered in terms of thedisplaced geometric axis. The nasal (lower) part of the lens is thicker.

FIG. 10(b) is a final Rx lens of power −4 Dioptres created from theblank in FIG. 7(a); curve (14) is 8 Dioptres centred on the optical axis(4). The optic zone width is ±45° for a rear vertex distance of 28 mm,with the temporal limit of the piano skirt of the lens being 98°.

FIG. 11(a) is a final Rx lens of power +4 Dioptres produced from thesemi-finished blank moulded against a back mould surface of similar formto the front of the lens shown in FIG. 7(c): curve (15) is −8.2 Dioptrescentred on axis (4) to limit the final lens thickness, curve (16) is 4Dioptres centred on axis (4). The optic zone is ±35° about the opticalaxis (4) and the pseudo piano temporal skirt (upper part of drawing)extends 87° from the forward line of sight for a rear vertex distance of28 mm.

FIG. 11(b) is a final Rx lens of power +4 Dioptres: curve (17) is 10.2Dioptres centred on axis (4) to limit the final lens thickness, curve(18) is 6 Dioptres centred on axis (4). The optic zone is ±40° about theoptical axis (4) and the pseudo piano temporal skirt (upper part ofdrawing) extends 95° from the forward line of sight for a rear vertexdistance of 28 mm.

FIG. 11(c) is a final Rx lens of power +4 Dioptres: curve (19) is 12.25Dioptres centred on axis (4) to limit the final lens thickness, curve(20 is 8 Dioptres centred on axis (4). The optic zone is ±48° about theoptical axis (4) and the pseudo piano temporal skirt (upper part ofdrawing) extends 98° from forward line of sight for a rear vertexdistance of 28 mm.

FIG. 12(a) is a schematic illustration of a pair of minus lens elementsaccording to the present invention of −3.0 D through power rotated abouttheir vertical optical axes by 20°.

FIGS. 12(b) and (c) show the resulting mean surface power andastigmatism contours after the rotation of the lenses in FIG. 12(a).

FIGS. 12(d) and (e) illustrate the resulting mean power and astigmatismcontours after subjecting the back surfaces of the lenses of FIG. 12(a)to a full correction of the required mean through power.

FIGS. 12(f) and (g) illustrate the resulting mean power and astigmatismcontours after subjecting the back surfaces of the lenses of FIG. 12(a)to a further full toric back surface correction.

FIGS. 12(h) and (i) illustrate the resulting mean power and astigmatismcontours after subjecting the back surfaces of the lenses of FIG. 12(a)to a further partial toric back correction.

FIGS. 12(j) and (k) illustrate the resulting mean power and astigmatismcontours after subjecting the back surfaces of the lenses of FIG. 12(a)to a partial mean power and partial toric back correction.

FIG. 13(a) is a schematic illustration of a pair of piano lens elementsaccording to the present invention of 3.0 D through power rotated abouttheir vertical optical axes by 20°.

FIGS. 13(b) and (c) show the resulting mean surface power andastigmatism contours after the rotation of the lenses in FIG. 12(a).

FIGS. 13(d) and (e) illustrate the resulting mean power and astigmatismcontours after subjecting the back surfaces of the lenses of FIG. 12(a)to a full correction of the required mean through power.

FIGS. 13(f) and (g) illustrate the resulting mean power and astigmatismcontours after subjecting the back surfaces of the lenses of FIG. 12(a)to a further full toric front surface correction.

FIGS. 13(h) and (i) illustrate the resulting mean power and astigmatismcontours after subjecting the back surfaces of the lenses of FIG. 12(a)to a further partial toric front correction.

FIG. 14(a) is a schematic illustration of a pair of aspheric minus lenselements according to the present invention of −3.0 D through powerrotated about their vertical optical axes by 20°.

FIGS. 14(b) and (c) show the resulting mean surface power andastigmatism contours after subjecting the lens elements to aspherisationof the front surface and a full toric back surface correction.

FIGS. 15 and 16 illustrate a series of laminate optical plus (+) lenselements.

FIG. 17 illustrates a laminate optical minus lens element.

FIG. 18 illustrates a laminate or integral surfaced minus lens elementwherein the thickness of the laminated assembly is adjusted by selectingback elements of different diameter, thus altering the size of theoptical zone of the final lens.

FIG. 19 illustrate optical lens elements including a temporal generallypiano extension of modified curvature.

FIGS. 21 to 29 illustrate plus and minus optical lens elements whosefront surfaces are described by the expression

sag=SAG R≦R0,

sag=SAG+DSAG R≧R0

and form both an optical zone giving the required Rx correction and aperipheral temporal zone with a simple spherical or toric back surface.

FIG. 21 shows a plus lens of power +2 Dioptres with a piano temporalextension.

FIGS. 22 and 23 show plus lenses of power +4 Dioptres. That in FIG. 22has a smooth transition of power to a piano temporal extension, beingdesigned with the parameter N=2. The lens in FIG. 23 has a lessdesirable discontinuity in front surface power, being designed with theparameter N=1.

FIGS. 24 and 25 show lenses of power 4 Dioptres. That in FIG. 24 has asmooth transition of power to a piano temporal extension, being designedwith the parameter N=2. The lens in FIG. 25 has a less desirablediscontinuity in front surface power, being designed with the parameterN=1.

FIGS. 26 to 28 illustrate similar plus and minus optical lens elementscreated by blending two different surfaces of standard conic design butof different powers corresponding to the optic zone and the temporalextension. Like the lens shown in FIG. 23, these lenses exhibitdiscontinuity of either tangential or sagittal curvature at thetransition between the two design regions. This requires, in turn, thatthe surface be optimised, so far as is possible, by standard ray tracingtechniques in order to minimise the astigmatism and blur introduced bythe transitional region between the optic zone and the temporalextension.

FIGS. 29 and 30 illustrate similar optical plus and minus lens elementsincluding a generally piano temporal extension.

EXAMPLE 1

An ophthalmic lens bearing a minus Rx is produced as follows:

These lenses may be produced as stock lenses or provided viasemi-finished blanks, as preferred. For a cast stock lens, the backmould will be unaltered from a conventional back mould for example ofthe Spectralite type. For a semi-finished blank, the rear ophthalmicsurface is ground and polished per standard procedure. In both cases,the principal difference is that the front Mould will have a peripherycurved sharply to the torus design. A side-fill tube gasket would appearappropriate to both product forms.

A semi-finished (S/F) blank is used normally to supply a range ofscripts from each base curve as well as accommodating differentpupillary distances (PD's) and different frame shapes and sizes. For allof these lens styles, a specific frame style may be used, so cut lensshape will not vary in a major way.

Nevertheless, the S/F blank has to provide for the defined Rx range, theindividual PD and the essential temporal extension curve. This curve issteeper the higher the minus script produced and steeper the larger theradius from optical center to temporal edge (i.e. the smaller the PD,all other factors constant).

The geometry of a S/F blank is generally as illustrated in FIG. 4. Thefront torus curve of the blank extends down the outer edge by at leastthe depth required for the highest recommended minus power for thatnominal base curve (including cylinder). It is not constant at allorientations. Each S/F blank is decentred to allow for a normal spreadof PD's. The selection of a particular radius on the blank to be thehorizontal meridian of the finished lens will define both the operablePD and the true power of the horizontal meridian Blanks may be providedwith ink markings and alignment callipers to allow correct orientationfor surface edging. However edging does not remove the desired temporalcurvature.

The optical axis of the optical lens element may be decentered relativeto the geometric axis of the lens element. The decentration may functionto improve optical performance in the forward direction of vision,whilst maintaining the geometry required for mounting in wrap-aroundframes. Preferable, the optical axis is decentered horizontally relativeto the geometric axis of the lens element. Alternatively, or inaddition, the optical axis is decentered vertically relative to thegeometric axis of the lens element to at least partially compensate forpantoscopic tilt. Where vertical decentration occurs, this may functionto ensure that the line of forward sight remains substantially parallelto the plane defined by the design axes of the lens.

A finished spherical power lens series are the exact parallel of the S/Fblank sketched above, except that the rear surface are also opticallyfinished.

EXAMPLE 2

An ophthalmic lens similar to that in Example 1 is produced, except thatthe geometric and optical centers of the lenses are not offset. Suchlenses are used with a frame system that allows the PD to be set via theattachment of the lens to the frame supports, rather than by offsettingthe geometric and optical centers of the lenses.

EXAMPLE 3

Single point turning apparatus for generation of the required surfaces(both spheres and cyls). Alternatively flexible fining and polishingpads may be used to complete the optic zone surface to a good opticalfinish and a minimal buffing of the rear temporal “ledge” is sufficient.The torus segment of the resultant lens is translucent although free ofgenerating marks. A gradient mirror coating over this area completes theRx.

EXAMPLE 4

An ophthalmic lens according to the present invention is laminated froma front and back wafer pair via a conventional lamination system, e.g.the Matrix™ system, U.S. Pat. Nos. 5,187,505, 5,149,181 and 5,323,192 toapplicants, the entire disclosure if which is incorporated herein byreference. The interface curve in a laminating system needs to haverotational symmetry about the optical axis in order for the cyl axis tobe selected according to the script. Accordingly lens wafers areprepared in which the geometric and optical centres of the lenses arenot offset.

The wafers are approximately 80 mm diameter with conventional optics incentral zones of about 55 mm diameter with temporal “torus” edges thatare more steeply curved. This is illustrated in FIGS. 5 and 6. Thetemporal extension effect is an excess sag of at least 10 to 15 mm. Thisis the critical feature of the design concept; asymmetric edging ofcompleted lenses creates the geometry aimed to conform to the brow. Thenasal side of the edged lens is fully spherical while elsewhere, theexcess sag reaches towards the brow around toward the temple.

EXAMPLE 5

A series of lenses of piano or negative refractive power according tothe present invention is produced from a conventional spherical S/Fblank of the form shown in FIG. 7(a) by first mounting the front(finished) optical surface of the blank on an eccentric tooling fixtureso that the axis of revolution for generating and polishing the rearsurface of the blank is offset from the nominal axis of the blank by anangle of (say) 20° or so. Next, an optical surface of exactly the samedioptric power as that of the front surface of the blank but centred onthe offset axis is produced on the rear (concave) surface of the blank.This results in a true piano lens with separate optical and geometricaxes. The form of the piano lens is reminiscent of a lens to whichbase-in prism has been applied, as the nasal side of the lens is thickerthan the temporal side (FIGS. 8(a), 9(a) and 10(a)). There is strictlyno prism applied, only that the piano lens is designed with tile sameoptical precision of any other part of the Rx range. The production of atrue piano with properly aligned optical axis is necessary for high basecurves for example 9 Dioptres and above, but is generally neglected inlower quality sunglasses.

Next, the piano lens is mounted via its rear surface to rotateeccentrically around the defined axis. Then a desired secondary opticalsurface centred on this optical axis is generated and polished on thefront surface. The power difference between this surface and theoriginal surface is the spherical power of the final Rx, with this newlyproduced optical surface defining the actual optical zone of the poweredlens (FIGS. 7(b) and (c)). The piano portion of the lens surrounding theoptical zone provides the temporal extension required for lens accordingto the invention. This increases as the base curve is increased, shownin FIGS. 7 through 10 for a −4 Dioptre Rx lens. For the examples in theFigures, the temporal extension increases from 88° to 98° temporal withbase curve increasing from 8 to 12 Dioptres. The corresponding opticzone widths range from ±35° to ±45° with increasing base curve.

Clearly, the order in which the two optical surfaces are created may bereversed if desired. This is generally the case when it is necessary toapply cylinder to the rear surface for correction of astigmatism.

For plus lenses according to the invention, the front optical surface ofthe S/F blank does not have a second optical surface imposed upon it.Rather, the rear surface has compound form shown in FIG. (11) for +4Dioptre Rx lenses. The compound rear surfaces of these lenses, i.e.curves (15)+(16), (17)+(18) and (19)+(20), are generated about theoptical axis using computer controlled equipment such as a Coburn IQgenerator or one of the several precision optical lathes available tothe industry and are polished to ophthalmic requirements by polishingwith flexible or inflatable polishing pads, as used in the industry. Theoptic zone is defined by the central optic on the rear surface of thefinished lens. Its breadth ranges from ±35° to ±48° as base curveincreases from 8 to 12 Dioptres, whilst the temporal reach grows from87° to 98°. Clearly, the same technology can be used to create minuspower lenses maintaining a simple front curve and designing a compoundrear surface to suit. It is also understood that all of the surfacesdescribed here can be imparted a cylindrical component (desirably on therear curves) to correct astigmatism.

In order to limit the total thickness of plus lenses, it is desirable tominimise the effect of the apparent base-in prism of the true pianolenses at these high base curves. The rear surface of the temporalextension of the plus lenses is therefore made slightly higher inspherical power than the front curve so that the temporal extension isof approximately constant thickness throughout. As a result, thetemporal extension has slight negative power, in the order of 0.25Dioptres for the highest base curves (about 12 Dioptres). Suchrefractive power is not noticeable to most wearers and we thereforerefer to the temporal extension as “pseudo-piano”.

All of the lenses described in this example may be produced by castingmonomer within moulds shaped to impart the described surface forms afterpolymerization. In this case, the compound surfaces for both plus andminus Rx lenses are preferably placed at the back of the tens element.Those surfaces are then produced as convex surfaces on the correspondingback mould, facilitating the process of mould manufacture. In such aconfiguration, plus Rx lenses and minus Rx lenses will have the samefront form so that the external appearance of the sunglass will beindependent of the prescription of the wearer. Cylinder for thecorrection of astigmatism may be introduced similarly be appropriatelyshaped back moulds oriented according to the desired prescription.Alternatively, mild cylinder up to 1.50 Dioptres or so can be impartedby grinding and polishing a secondary curve on the front surface of alens of the appropriate spherical power. This would suit approximately95% of cylindrical corrections for most populations.

EXAMPLE 6 A Minus Lens

The following is an example that describes a lens element constructedaccording to the present invention.

EXAMPLE 6A Prior Art

A lens was constructed with 0° C. pantoscopic tilt to achieve aprescribed through power of −3.0 D and 0.00 D of cyl using the followingcurves (see FIG. 12(a)).

Spherical front curve of 6.00 D (1.530)

Spherical back curve of 9.18 D (1.530)

This results in a lens with a distance vision correction such that

Mean through power=−3.00 D

Resultant on-axis optical cyl=0.00 D

Rotate the lens in the temporal direction about the vertical opticalaxis by 20° (See FIG. 12(a))

This gives the following optical results

Mean through power=−3.33 D

Resultant on-axis optical cyl=0.42 D @ 90°

FIGS. 13(b) and (c) show the resulting mean surface power andastigmatism contours relative to lens surface coordinates.

EXAMPLE 6B Prior Art

Full mean power correction.

The back surface curve was adjusted to achieve full correction of therequired mean through power of −3.00 D. This results in the followingoptical results

Back surface curvature=8.87 D (1.530)

Mean through power=−3.00 D

Resultant on-axis optical cyl=0.36 D @ 90°

FIGS. 12(d) and (e) illustrate the resulting mean power and astigmatismcontours relative to lens surface coordinates.

EXAMPLE 6C Prior Art

Full mean power and full astigmatism toric back surface correction. Theback surface curve was adjusted to achieve full correction of therequired mean through power of −3.00 D and also a toric back surfacecorrection was applied to result in a full astigmatism correction. Thisresults in the following optical results:

Mean back surface curvature=8.87 D (1.530)

Equatorial back surface power=8.69 D (1.530)

Meridional back surface power=9.05 D (1.530) Toric 0.36 D @0°

Mean through power=−3.00 D

Resultant on-axis optical cyl=0.00 D

FIGS. 12(f) and (g) illustrate the resulting mean power and astigmatismcontours relative to lens surface coordinates.

EXAMPLE 6D

Full mean power and partial toric back correction.

The back surface curve was adjusted to achieve full correction of therequired mean through power of −3.00 D. A partial toric back surfacecorrection was applied to balance the off-axis and on-axis astigmaticerrors. This gives the following optical results.

Mean back surface curvature=8.87 D (1.530)

Equatorial back surface power=8.76 D (1.530)

Meridional back surface power=9.00 D (1.530) Toric 0.25 D @ 0°

Mean through power=−3.00 D

Resultant on-axis optical cyl=0.11 D @ 90°

FIGS. 12(h) and (i) illustrate the resulting astigmatism contours andmean power contours relative to lens surface coordinates.

EXAMPLE 6E

Partial mean power and partial toric back correction.

Adjust the central mean through power to partially correct the requiredthrough power and reduce the amount of un-accommodatable off-axis powererror. A partial toric back surface correction is applied to balance theoff-axis and on-axis astigmatic errors. This results in the followingoptical results:

Mean back surface curvature=9.12 D (1.530)

Equatorial back surface power=8.98 D (1.530)

Meridional back surface power=0.26 D (1.530) Toric 0.27 D @ 0°

Mean through power=−3.25 D

Resultant on-axis optical cyl=0.12 D @ 90°

FIGS. 12 (j) and (k) illustrate the resulting astigmatism contours andmean power contours relative to lens surface coordinates.

EXAMPLE 7 A Plus Lens

The following is an example that describes a lens constructed accordingto the present invention.

EXAMPLE 7A Prior Art

Construct a lens with 0° C. pantoscopic tilt to achieve a prescribedthrough power of +3.0 D and 0.00 D of cyl using the following curves(see FIG. 13(a)).

Spherical front curve of 6.00 D (1.530)

Spherical back curve of 2.92 D (1.530)

This results in a lens with a distance vision correction such that

Mean through power=+3.00 D

Resultant on axis optical cyl=0.00 D

Rotate the lens in the temporal direction about the vertical opticalaxis by 20° (see FIG. 13(a)).

This gives the following optical results

Mean through power=+3.36 D

Resultant on axis optical cyl=0.46 D @ 90°

FIGS. 13(b) and (c) show the resulting mean power and astigmatismcontours relative to lens surface coordinates.

EXAMPLE 7B Prior Art

Full mean power correction.

The back surface curve was adjusted to achieve full correction of therequired mean through power of +3.00 D. This results in the followingoptical results

Spherical front curvature=6.00 D (1.530)

Back surface curvature=3.23 D (1.530)

Mean through power=+3.00 D

Resultant on axis optical cyl=0.41 D @ 90°

FIGS. 13(d) and (e) illustrate the mean power and resulting astigmatismcontours relative to lens surface coordinates.

EXAMPLE 7C Prior Art

Full mean power and full astigmatism toric front surface correction. Theback surface curve was adjusted to achieve full correction of therequired mean through power of +3.00 D and also a toric front surfacecorrection was applied to result in a full astigmatism correction. Thisresults in the following optical results:

Mean back surface curvature=3.32 D (1.530)

Equatorial front surface power=5.82 D (1.530)

Meridional front surface power=6.18 D (1.530) Toric 0.36 D @ 0°

Mean through power=+3.00 D

Resultant on axis optical cyl=0.00 D

FIGS. 13(f) and (g) illustrate the mean power and resulting astigmatismcontours relative to lens surface coordinate.

EXAMPLE 7D

Full mean power and partial toric front correction.

The back surface curve was adjusted to achieve full correction of therequired mean through power of +3.00 D. A partial toric front surfacecorrection was applied to balance the off-axis and on-axis astigmaticerrors. This gives the following optical results:

Mean back surface curvature=3.32 D (1.530)

Equatorial front surface power=5.91 D (1.530)

Meridional front surface power=6.09 D (1.530) Toric 0.18 D @ 0°

Mean through power=+3.00 D

Resultant on axis optical cyl=0.22 D @ 90°

FIGS. 13(h) and (i) illustrate the mean power and resulting astigmatismcontours and mean power contours relative to lens surface coordinates.

EXAMPLE 8 Aspheric Minus Lens

Aspheric front surface and toric back surface corrected (see FIG. 14(a))

The back surface was adjusted to achieve full correction of the requiredmean through power of −3.00 D and also a toric back surface correctionwas applied to result in a full astigmatic correction in a mannersimilar to Example 6C above.

An aspheric front surface correction was applied to reduce off-axisastigmatic and power errors.

This results in the following optical results:

Mean back surface curvature=9.05 D (@ 1.530)

Equatorial front surface power=8.67 D (@ 1.530)

Meridional front surface power=9.05 D (@ 1.530)

Mean through power=−3.00 D

Resultant on axis optical cyl=0.00 D

Aspheric Front Surface

The height of the front surface at a radius, r, is given by the formula:

Z=a ₀ r ⁰ +a ₁ r ¹ +a ₂ r ₂ +a ₃ r ³ +a ₄ r ⁴ +a ₅ r ⁵ +a ₆ r ⁶ +a ₇ r ₇+a ₈ r ⁸

where a₀ to a₈ are constant numerical coefficients.

Base curve=6.00 D

a₀=a₁=a₃=a₅=a₇=0.0

a₂=0.5660377×10⁻²

a₄=−0.19050×10⁻⁶

a₆=0.65054×10⁻¹⁰

a₈=0.17067×10⁻¹³

FIGS. 14(b) and (c) illustrate the resulting mean power and astigmatismcontours relative to lens surface co-ordinates.

EXAMPLE 9 Aspheric Surface Lens Element

An optical lens element including a peripheral temporal zone was formedfrom a front 9 base aspheric piano element and a number of rearspherical plus lens elements laminated to the rear surface thereof.

The surfaces are defined utilising a standard mathematical approach. Thesurfaces have the characteristics specified in Table 1 below:

The resulting lens element is illustrated schematically in FIG. 15.

EXAMPLE 10

Example 9 was repeated utilising rear lens elements of the sanrefractive power (+4 and +6 Dioptres) but of reduced diameter. The opticzone of each is reduced in angular extent, while the overall laminatedlenses ε substantially thinner.

The surfaces are defined utilising a standard mathematical approach. Thesurfaces have the characteristics specified in Table 2 below.

The resulting lens element is illustrated schematically in FIG. 16.

EXAMPLE 11

Example 9 was repeated utilising rear lens elements of −4 and −8 Dioptrerefractive power, wherein the edges of these elements were angledparallel to the line of sight at those edges, or more steeply, so thatthe wearer experiences a sudden change from the optic zone to the pianotemple extension without any intermediate optical transition ordistortion.

The surfaces are defined utilising a standard mathematical approach. Thesurfaces have the characteristics specified in Table 3 below.

The resulting lens element is illustrated schematically in FIG. 17.

EXAMPLE 12

An optical lens element including a peripheral temporal zone was formedfrom a front 9D base aspheric front surface together a rear −4D and −8Dbase spherical rear surface. The rear surface may be formed either bylamination as described in example 1 above or may be integrally formedby cutting on mill or on standard optical processing equipment with anadditional final polishing step to round off the sharp edge which wouldotherwise exist at the boundary of the optic zone and the integraltemple extension.

The surfaces are defined utilising a standard mathematical approach. Thesurfaces have the characteristics specified in Table 4 below.

The resulting lens element is illustrated schematically in FIG. 18.

EXAMPLE 13 Torus Surface Lens Element

An optical lens element is formed utilising a circular front surface andconic rear surfaces with a modified piano temporal extension.

The front or rear surfaces may be formed from front and rear lenselements laminated together or may be integrally formed by cutting on anNC mill.

The surfaces are defined utilising the modified mathematical formulaedescribed above.

The surfaces have the characteristics specified in Table 5 below.

The resulting lens element is illustrated schematically in FIG. 19.

A similar lens element to that in FIG. 19 has the characteristicsspecified in Table 6 below.

It is noteworthy that the front piano described in this example has anoptic zone and a temporal region of high curvature which together definea piano lens with essentially constant thickness from the central regionthrough and including the temporal extension. This is an alternative anddifferent approach to achieving the piano sunglass or safety glass lensattributes described in U.S. Pat. No. 5,604,547 to Gentex.

A further aspheric front surface correction was applied to eliminateoff-axis astigmatic and power errors within the piano element, similarlyto Example 8 above. This gave the following:

Central Front Curve=9.0 D (@ 1.4999)

Mean Through power=0.1×10⁻² D

Resultant on axis optical cyl=0.1×10⁻² D

Maximum off-axis cyl=0.2 D

For which the constant numerical coefficients were

a₀=a₁=a₂=a₃=a₅=a₇=0.0

a₂=0.849057×10⁻²

a₄=0.610000×10⁻⁶

a₆=0.150000×10⁻⁹

EXAMPLE 14

Example 13 was repeated utilising 9 D design for the front surface ofthe optic zone and a 7 D circular back surface to define an integrallens element of through power +2 D. The front generating curve for thetemporal extension was 4.5 D and resulted in a temporal zone with slightpositive refractive power.

The surfaces are defined utilising the modified mathematical approachdescribed above with N=2 and a negative value for the parameter a(−1.2). The surfaces have the characteristics specified in Table 7below.

The resulting lens element is illustrated schematically in FIG. 21.

Obviously the lens element may be rotated or decentred to improvecosmetic relationship with a wearers face without the need to introducehigher lens curvature.

EXAMPLE 15

Example 14 was repeated utilising a front surface of 12.00 D for theoptic zone and a back surface of 8.00 D to define an integral lenselement of +4.00 D through power. The front generating curve for thetemporal extension was 4.25 D.

The resulting lens element is illustrated in FIG. 22 and its surfacecharacteristics are specified in Table 8. In this case the temporalextension changes smoothly from the power of the optic zone (+4.00 D) topiano.

EXAMPLE 16

Example 15 was again repeated utilising a front generating curve for thetemporal extension of 12.00 D and setting N=1, rather than N=2 in theprevious example of FIG. 22.

The resulting lens element is illustrated in FIG. 23 and its surfacecharacteristics are specified in Table 9. In this case, the temporalextension is piano, the diameter of the optic zone is reduced.

EXAMPLE 17

Example 14 was repeated utilising a front surface of 4.50 D for theoptic zone and a back surface of 8.50 D to define an integral lenselement of −4.00 D through power. The front generating curve for thetemporal extension was 2.50 D.

The resulting lens element is illustrated in FIG. 24 and its surfacecharacteristics are specified in Table 10. In this case the temporalextension changes smoothly from the power of the optic zone (−4.00 D) topiano.

EXAMPLE 18

Example 17 was again repeated utilising a front generating curve for thetemporal extension of 11.00 D and setting N=1, rather than N=2 in theprevious example of FIG. 24.

The resulting lens element is illustrated in FIG. 25 and its surfacecharacteristics are specified in Table 11. In this case, the temporalextension is piano, the lens has a thinner centre and the diameter ofthe optic zone is reduced.

EXAMPLE 19 Plus Lens

Example 14 was repeated utilising a front generating curve for thetemporal extension of 8.00 D. A conic back surface of 8.0 D and a frontsurface of 11.0 D was used to define a lens of through power of +3.0 Dand a generally piano temporal extension with a narrow edge thickness.

The resulting lens is illustrated in FIG. 26. The lens exhibits adiscontinuity at the transition between the two design zones. Thesurface of FIG. 26 has the characteristics specified in Table 12.

EXAMPLE 20

Example 19 was repeated to produce a +1.0 D lens with an 8.0 D basetemporal extension.

The resulting lens is illustrated in FIG. 27. The surface of FIG. 27 hasthe characteristics specified in Table 13.

EXAMPLE 21

Example 19 was repeated to produce a −2.0 D lens with an 8.0 D temporalextension.

The resulting lens is illustrated in FIG. 28. The surface of FIG. 28 hasthe characteristics specified in Table 14.

EXAMPLE 22

An optical lens element including a peripheral temporal zone was formedfrom a front +11 D base aspheric front surface and an +8 D basespherical back surface to provide a +3 D lens element.

The curvature in the temporal region of the front surface is modifiedsuch that it corresponds to the curvature of the back surface, thusdefining a piano temporal extension.

The surfaces are designed utilising the modified mathematical formulaedescribed above. Specifically, the lens element has a spherical or toricback surface whose curvature is chosen to conform with the wrap-aroundframe. The front surface of the lens element is an aspheric surface withthree distinct zones. The central prescription region is developed toprovide the desired through power and is optimised to minimise off-axisastigmatic and power errors. The front surface of the lens element atthe periphery or temporal extension region is a sphere designed to givethe lens in this region no through power (plano) as in anon-prescription sunlens. Between the inner and outer region the surfaceis developed from a polynomial spline whose purpose is to smoothly blendthe central region with the periphery. Although the surface is designedas a full surface of rotation, only a portion of this surface is used inthe actual frame. Accordingly the lens form may be manufactured in sucha way that only part of the full surface of rotation is created prior toedging to fit the frame.

The surfaces have the characteristics specified in Table 15 below.

The resulting lens element is illustrated schematically in FIG. 29.

EXAMPLE 23

Example 22 was repeated utilising a 5.0 D base aspherical front surfaceand an 8.0 D base spherical back surface to define a −3 D base lenselement.

The surfaces have the characteristics specified in Table 16 below.

The resulting lens element is illustrated in FIG. 30.

TABLE 1 Polycarbonate ASL B A2 A4 A6 A8 r D ASPHERE 8 7.60E−03 3.00E.077.00E−11 0.00E+00 65.75 8.97 SPHERES 3 2.54E−03 1.64E−08 2.12E−133.43E−18 196.67 3.00 5 4.24E−03 7.61E−08 2.73E−12 1.23E−16 118.00 5.008.97 7.60E−03 4.39E−07 5.08E−11 7.33E−15 65.77 8.97 R 8ASL 3 5 8.97 −50−45 −40 −35 −30 7.138 8.740 8.739 −25 4.887 6.436 7.542 6.436 −20 3.0945.861 6.570 4.614 −20 3.094 5.861 6.570 4.614 −15 1.727 5.414 5.8203.233 −10 0.763 5.095 5.287 2.265 −5 0.190 4.905 4.969 1.690 0 0.0004.841 4.863 1.500 5 0.190 4.905 4.969 1.690 10 0.763 5.095 5.287 2.26515 1.727 5.414 5.820 3.233 20 3.094 5.861 6.570 4.614 25 4.887 6.4367.542 6.436 30 7.138 8.740 8.739 35 9.894 11.581 40 13.221 15.043 4517.210 19.240

TABLE 2 Polycarbonate ASL B A2 A4 A6 A8 r D ASPHERE 8 7.60E−03 3.00E.077.00E−11 0.00E+00 65.75 8.97 SPHERES 3 2.54E−03 1.64E−08 2.12E−133.43E−18 196.67 3.00 5 4.24E−03 7.61E−08 2.73E−12 1.23E−16 118.00 5.008.97 7.60E−03 4.39E−07 5.08E−11 7.33E−15 65.77 8.97 R 8ASL 3 5 8.97 −50−45 −40 −35 −30 7.138 8.739 −25 4.887 6.179 6.436 −20 3.094 4.520 5.2074.614 −20 3.094 4.520 5.207 4.614 −15 1.727 4.073 4.457 3.233 −10 0.7633.754 3.924 2.265 −5 0.190 3.564 3.606 1.690 0 0.000 3.500 3.500 1.500 50.190 3.564 3.606 1.690 10 0.763 3.754 3.924 2.265 15 1.727 4.073 4.4573.233 20 3.094 4.520 5.207 4.614 25 4.887 6.179 6.436 30 7.138 8.739 359.894 11.581 40 13.221 15.043 45 17.210 19.240

TABLE 3 Polycarbonate ASL B A2 A4 A6 A8 r D ASPHERE 8 7.60E−03 3.00E.077.00E−11 0.00E+00 65.75 8.97 SPHERES 17 1.44E−02 2.99E−06 1.24E−096.44E−13 34.71 17.00 13 1.10E−02 1.34E−06 3.25E−10 9.85E−14 45.38 13.008.97 7.60E−03 4.39E−07 5.08E−11 7.33E−15 65.77 8.97 R 8ASL 17 13 8.97−50 −45 −40 −35 −30 7.138 12.800 8.239 −25 4.887 9.002 5.936 −20 3.0947.758 6.144 4.114 −20 3.094 7.837 6.144 4.114 −15 1.727 4.909 4.0502.733 −10 0.763 2.972 2.615 1.765 −5 0.190 1.862 1.776 1.190 0 0.0001.500 1.500 1.000 5 0.190 1.862 1.776 1.190 10 0.763 2.972 2.615 1.76515 1.727 4.909 4.050 2.733 20 3.094 7.837 6.144 4.114 25 4.887 9.0025.936 30 7.138 12.800 8.239 35 9.894 11.081 40 13.221 14.543 45 17.21018.740

TABLE 4 Polycarbonate ASL B A2 A4 A6 A8 r D ASPHERE 8 7.60E−03 3.00E.077.00E−11 0.00E+00 65.75 8.97 SPHERES 17 1.44E−02 2.99E−06 1.24E−096.44E−13 34.71 17.00 13 1.10E−02 1.34E−06 3.25E−10 9.85E−14 45.38 13.008.97 7.60E−03 4.39E−07 5.08E−11 7.33E−15 65.77 8.97 R 8ASL 17 13 8.97−50 −45 −40 −35 −30 7.138 10.733 10.794 8.329 −25 4.887 9.038 9.0025.936 −20 3.094 7.758 6.144 4.114 −15 1.727 4.909 4.050 2.733 −10 0.7632.972 2.615 1.765 −5 0.190 1.862 1.776 1.190 0 0.000 1.500 1.500 1.000 50.190 1.862 1.776 1.190 10 0.763 2.972 2.615 1.765 15 1.727 4.101 4.0502.733 20 3.094 7.837 6.144 4.114 25 4.887 9.038 9.002 5.936 30 7.13810.733 10.794 8.239 35 9.894 12.872 12.997 11.081 40 13.221 16.11715.821 14.543 45 17.210 19.360 19.378 18.740

TABLE 5 Highly Curved Wrap Around Piano Lens Element B A2 A4 A6 A8 r DFront Asphere 9 7.60E−03 3.00E−07 7.00E−11 0.00E+00 65.75 8.97 Back 97.63E−03 4.44E−07 5.16E−11 7.51E−15 65.56 9.00 Temples 20 0.00E+004.87E−07 2.80E−09 2.01E−12 0.00 Sag =SAG + αSAG^(N) R0 R 9 Sag1 Sag2 α1N α2 −22.5 12 1 15 −22.5 12 1 15 −22.5 12 1 15 −22.5 −35 9.894 11.46313.542 12 1 15 −22.5 −30 7.136 7.329 8.978 12 1 15 −22.5 −25 4.887 4.8896.439 12 1 15 −22.5 −20 3.094 3.094 4.625 12 1 15 −22.5 −20 3.094 3.0944.625 12 1 15 −22.5 −15 1.727 1.727 3.239 12 1 15 −22.5 −10 0.763 0.7632.267 12 1 15 −22.5 −5 0.190 0.190 1.691 12 1 15 −22.5 0 0.000 0.0001.500 12 1 15 22.5 5 0.190 0.190 1.691 12 1 15 22.5 10 0.763 0.763 2.26712 1 15 22.5 15 1.727 1.727 3.239 12 1 15 22.5 20 3.094 3.094 4.625 12 115 22.5 25 4.887 4.889 6.439 12 1 15 22.5 30 7.138 7.329 8.978 12 1 1522.5 35 9.894 11.463 13.582 12 1 15 22.5 40 13.221 19.877 23.420 12 1 15

TABLE 6 Highly Curved Wrap Around Piano Lens Element B A2 A4 A6 A8 r DFront Asphere 9 7.60E−03 3.00E−07 7.00E−11 0.00E+00 65.75 8.97 Back 97.63E−03 4.44E−07 5.16E−11 7.51E−15 65.56 9.00 Temples 9 7.63E−034.44E−07 5.16E−11 7.51E−15 65.56 9.00 Sag = SAG + αSAG^(N) R0 R 9 Sag1Sag2 α1 N α2 −25 2 2 2.5 −25 2 2 2.5 −25 2 2 2.5 −25 −35 9.894 11.07113.053 2 2 2.5 −25 −30 7.138 7.211 8.830 2 2 2.5 −25 −25 4.887 4.8876.436 2 2 2.5 −25 −20 3.094 3.094 4.625 2 2 2.5 −25 −20 3.094 3.0944.625 2 2 2.5 −25 −15 1.727 1.727 3.239 2 2 2.5 −25 −10 0.763 0.7632.267 2 2 2.5 −25 −5 0.190 0.190 1.691 2 2 2.5 −25 0 0.000 0.000 1.500 22 2.5 25 5 0.190 0.190 1.691 2 2 2.5 25 10 0.763 0.763 2.267 2 2.5 25 151.727 1.727 3.239 2 2 2.5 25 20 3.094 3.094 4.625 2 2 2.5 25 25 4.8874.887 6.436 2 2 2.5 25 30 7.138 7.211 8.830 2 2 2.5 25 35 9.894 11.07113.092 2 2 2.5 25 40 13.221 19.271 22.662 2 2 2.5

TABLE 7 B A2 A4 A6 A8 r D Front Surface 9 7.63E−03 4.44E−07 5.16E−117.51E−15 65.56 9.00 9 7.63E−03 4.44E−07 5.16E−11 7.51E−15 65.56 9.00Back Surface 7 5.93E−03 2.09E−07 1.47E−11 1.29E−15 84.29 7.00 Fronttemples 5.75 4.87E−03 1.16E−07 5.49E−12 3.26E−16 102.61 5.75 CenterThickness 2.61 (mm) Edge Thickness 1.00 (40 mm) RO R 9 9 7 DSAG sag α N−23.25 −50 22.94 3.55 −1 2 −23.25 −45 17.82 2.33 −1 2 −23.25 −40 13.601.38 −1 2 −23.25 −35 10.12 0.67 −1 2 −23.25 −30 7.27 0.22 −1 2 −23.25−25 4.95 4.95 6.40 0.01 −1 2 −23.25 −20 3.13 3.13 5.02 0.05 −1 2 −23.25−20 3.13 3.13 5.02 0.05 −1 2 −23.25 −15 1.74 1.74 3.96 0.33 −1 2 −23.25−10 0.77 0.77 3.21 0.86 −1 2 −23.25 −5 0.19 0.19 2.76 1.64 −1 2 −23.25 00.00 0.00 2.61 2.67 −1 2 −23.25 5 0.19 0.19 2.76 3.97 −1 2 −23.25 100.77 0.77 3.21 5.54 −1 2 −23.25 15 1.74 1.74 3.96 7.40 −1 2 −23.25 203.13 3.13 5.02 9.56 −1 2 −23.25 25 4.95 4.95 6.40 0.01 4.95 −1 2 −23.2530 7.27 7.27 8.13 0.22 7.22 −1 2 −23.25 35 10.12 10.22 0.89 9.33 −1 2−23.25 40 13.60 12.70 1.38 11.71 −1 2

TABLE 8 B A2 A4 A6 A8 r D Front Surface 12 1.02E−02 1.05E−06 2.18E−105.62E−14 49.17 12.00 12 1.02E−02 1.05E−06 2.18E−10 5.62E−14 49.17 12.00Back Surface 8 6.78E−03 3.12E−07 2.86E−11 3.29E−15 73.74 8.00 Fronttemples 4.25 3.60E−03 4.67E−08 1.21E−12 3.93E−17 138.82 4.25 CenterThickness 4.55 (mm) Edge Thickness 0.91 (40 mm) RO R 12 12 8 DSAG sag αN −17.5 −50 37.59 3.86 −1.425 2 −17.5 −45 27.66 2.75 −1.425 2 −17.5 −4020.22 1.84 −1.425 2 −17.5 −35 14.56 1.11 −1.425 2 −17.5 −30 10.20 0.56−1.425 2 −17.5 −25 6.83 6.83 8.92 0.20 −1.425 2 −17.5 −20 4.25 4.25 7.310.02 −1.425 2 −17.5 −20 4.25 4.25 7.31 −1.425 2 −17.5 −15 2.34 2.34 6.09−1.425 2 −17.5 −10 1.03 1.03 5.23 −1.425 2 −17.5 −5 0.25 0.25 4.72−1.425 2 −17.5 0 0.00 0.00 4.55 −1.425 2 −17.5 5 0.25 0.25 4.72 −1.425 2−17.5 10 1.03 1.03 5.23 −1.425 2 −17.5 15 2.34 2.34 6.09 −1.425 2 −17.520 4.25 4.25 7.31 10.02 −1.425 2 −17.5 25 6.83 6.83 8.92 0.20 6.77−1.425 2 −17.5 30 10.20 10.93 0.56 9.75 −1.425 2 −17.5 35 14.56 13.381.13 12.73 −1.425 2 −17.5 40 20.22 16.33 1.84 15.42 −1.425 2

TABLE 9 B A2 A4 A6 A8 r D Front Surface 12 1.02E−02 1.05E−06 2.18E−105.62E−14 49.17 12.00 12 1.02E−02 1.05E−06 2.18E−10 5.62E−14 49.17 12.00Back Surface 8 6.78E−03 3.12E−07 2.86E−11 3.29E−15 73.75 8.00 FrontTemples 12 0.00E+00 1.05E−06 2.18E−10 5.62E−14 0.00 Center Thickness(mm) 4.55 Edge Thickness (40 mm) 0.84 R0 R 12 12 8 DSAG sag α N −15 −5037.59 2.10 −10 1 −15 −45 27.66 1.05 −10 1 −15 −40 20.22 0.47 −10 1 −15−35 14.56 0.18 −10 1 −15 −30 10.20 0.06 −10 1 −15 −25 6.83 6.83 8.920.01 −10 1 −15 −20 4.25 4.25 7.31 −10 1 −15 −20 4.25 4.25 7.31 −10 1 −15−15 2.34 2.34 6.09 −10 1 −15 −10 1.03 1.03 5.23 −10 1 −15 −5 0.25 0.254.72 −10 1 −15 0 0.00 0.00 4.55 −10 1 −15 5 0.25 0.25 4.72 −10 1 −15 101.03 1.03 5.23 −10 1 −15 15 2.34 2.34 6.09 −10 1 −15 20 4.25 4.25 7.31−10 1 −15 25 6.83 6.83 8.92 0.01 6.72 −10 1 −15 30 10.20 10.93 0.06 9.64−10 1 −15 35 14.56 13.38 0.18 12.73 −10 1 −15 40 20.22 16.33 0.47 15.50−10 1

TABLE 10 B A2 A4 A6 A8 r D Front Surface 4.5 3.81E−03 5.55E−08 1.61E−125.87E−17 131.11 4.50 4.5 3.81E−03 5.55E−08 1.61E−12 5.87E−17 131.11 4.50Back Surface 8.5 7.20E−03 3.74E−07 3.88E−11 5.03E−15 69.41 8.50 FrontTemples 2.5 2.12E−03 9.51E−09 8.54E−14 9.58E−19 236.00 2.50 CenterThickness (mm) 1 Edge Thickness 4.51 (40 mm) R0 R 4.5 4.5 8.5 DSAG sag αN −15 −50 9.91 2.61 1.65 2 −15 −45 7.96 1.91 1.65 2 −15 −40 6.25 1.331.65 2 −15 −35 4.76 0.85 1.65 2 −15 −30 3.48 0.48 1.65 2 −15 −25 2.412.41 5.66 0.21 1.65 2 −15 −20 1.53 1.53 3.94 0.05 1.65 2 −15 −20 1.531.53 3.94 0.05 1.65 2 −15 −15 0.86 0.86 2.64 0.00 1.65 2 −15 −10 0.380.38 1.72 0.05 1.65 2 −15 −5 0.10 0.10 1.18 0.21 1.65 2 −15 0 0.00 0.001.00 0.48 1.65 2 −15 5 0.10 0.10 1.18 0.85 1.65 2 −15 10 0.38 0.38 1.721.33 1.65 2 −15 15 0.86 0.86 2.64 1.91 1.65 2 −15 20 1.53 1.53 3.94 2.611.65 2 −15 25 2.41 2.41 5.66 0.21 2.48 1.65 2 −15 30 3.48 7.82 0.48 3.851.65 2 −15 35 4.76 10.47 0.85 5.95 1.65 2 −15 40 6.25 13.67 1.33 9.161.65 2

TABLE 11 B A2 A4 A6 AB r D Front Surface 4.5 3.81E−03 5.55E−08 1.61E−125.87E−17 131.11 4.50 4.5 3.81E−03 5.55E−08 1.61E−12 5.87E−17 131.11 4.50Back Surface 8.5 7.20E−03 3.74E−07 3.88E−11 5.03E−15 69.41 8.50 FrontTemples 11 0.00E+00 8.10E−07 1.41E−10 3.06E−14 0.00 Center Thickness(mm) 1 Edge Thickness 3.95 (40 mm) R0 R 4.5 4.5 8.5 DSAG sag α N −15 −509.91 1.54 10 1 −15 −45 7.96 0.78 10 1 −15 −40 6.25 0.36 10 1 −15 −354.76 0.14 10 1 −15 −30 3.48 0.04 10 1 −15 −25 2.41 2.41 5.66 0.01 10 1−15 −20 1.53 1.53 3.94 0.00 10 1 −15 −20 1.53 1.53 3.94 0.00 10 1 −15−15 0.86 0.86 2.64 0.00 10 1 −15 −10 0.38 0.38 1.72 0.00 10 1 −15 −50.10 0.10 1.18 0.01 10 1 −15 0 0.00 0.00 1.00 0.04 10 1 −15 5 0.10 0.101.18 0.14 10 1 −15 10 0.38 0.38 1.72 0.36 10 1 −15 15 0.86 0.86 2.640.78 10 1 −15 20 1.53 1.53 3.94 1.54 10 1 −15 25 2.41 2.41 5.66 0.012.41 10 1 −15 30 3.48 7.82 0.04 3.83 10 1 −15 35 4.76 10.47 0.14 6.07 101 −15 40 6.25 13.67 0.36 9.73 10 1

TABLE 12 Lens Rx 3.00 Index 1.59 Center Depth 2.10 Extension Power 0Edge Thickness 1.00 Optic Diameter 0 Center Thickness 3.10 B A0 A2 A4 A6A8 r D Center Optic 11.00 −3.00 9.32E−03 8.19E−07 1.41E−10 3.06E−1453.64 11.00 10.75 −2.83 9.11E−03 7.56E−07 1.26E−10 2.60E−14 54.88 10.7510.50 −2.55 8.00E−03 7.05E−07 1.12E−10 2.21E−14 56.19 10.50 10.25 −2.488.69E−03 6.55E−07 9.89E−11 1.87E−14 57.56 10.25 10.00 −2.30 8.47E−036.09E−07 8.74E−11 1.57E−14 59.00 10.00 9.75 −2.13 8.26E−03 5.64E−077.70E−11 1.31E−14 60.51 9.75 9.50 −1.95 8.05E−03 5.22E−07 6.76E−111.10E−14 62.11 9.50 9.25 −1.78 7.84E−03 4.82E−07 5.92E−11 9.09E−15 63.789.25 9.00 −1.60 7.63E−03 4.44E−07 5.16E−11 7.51E−15 65.56 9.00 8.75−1.43 7.42E−03 4.08E−07 4.48E−11 6.16E−15 67.43 8.75 8.50 −1.25 7.20E−033.74E−07 3.88E−11 5.03E−15 69.41 8.50 8.25 −1.08 6.99E−03 3.42E−073.34E−11 4.08E−15 71.52 8.25 Extension Frame 8.00 −0.90 6.78E−033.12E−07 2.86E−11 2.29E−15 73.75 8.00 Back Optic 8.00 0.10 8.78E−033.12E−07 2.86E−11 3.29E−15 73.75 8.00 8.00 0.10 6.78E−03 3.12E−072.86E−11 3.29E−15 73.75 8.00 Sag Front Frame Back R Xtn 11.0 8 8 −30.006.169 6.477 6.477 −25.00 3.182 4.467 4.467 −20.00 0.868 2.864 2.864−15.00 −0.860 1.642 1.642 −10.00 −2.060 0.781 0.781 −5.00 −2.766 0.2700.270 0.00 −3.000 0.100 0.100 5.00 −2.766 0.270 0.270 10.00 −2.060 0.7810.781 15.00 −0.860 1.642 1.642 20.00 0.868 0.868 2.864 2.864 Thickness25.00 3.182 3.199 4.467 4.467 1.268 25.07 3.218 3.252 4.492 4.492 1.24025.28 3.329 3.372 4.567 4.567 1.195 25.63 3.516 3.555 4.695 4.695 1.14026.11 3.783 3.798 4.877 4.877 1.079 26.74 4.137 4.099 5.117 5.117 1.01827.50 4.584 4.457 5.419 5.419 0.962 28.40 5.134 4.872 5.789 5.789 0.91729.44 5.80 5.343 6.233 6.233 0.890 30.63 6.595 5.871 6.759 6.759 0.88831.94 7.539 6.455 7.377 7.377 0.922 33.40 8.652 7.097 8.097 8.097 1.00035.00 9.963 7.933 8.933 8.933 1.000 40.00 14.766 10.884 11.884 11.8841.000 45.00 20.882 14.400 15.400 15.400 1.000 50.00 18.573 19.573 19.573

TABLE 13 Lens Rx 1.0 Extension Power 0.00 Center Thickness 2.43 OpticDiameter 60 Edge Thickness 1.000 Spectacle Aperture 85 Material:Polycarbonate B A2 A4 A6 A8 r D Front Optic 9.0 7.63E−03 4.44E−075.16E−11 7.51E−15 65.56 9.00 Extension 8 6.78E−03 3.13E−07 2.86E−113.29E−15 73.75 8.00 Frame 8 6.78E−03 3.12E−07 2.86E−11 3.29E−15 73.758.0x Back Optic 8 6.78E−03 3.12E−07 2.86E−11 3.29E−15 73.75 8.00 SagBack Front Extn Frame R 8.00 9.0 8 8 −50 −45 −40 −35 −30 −25 4.49651032.6540148 3.8665103 −20 2.8936411 0.8220304 2.2636411 −20 2.89364110.8253341 2.2636411 −15 1.6715342 −0.560829 1.0415342 −10 0.8111113−1.532799 0.1811113 −5 0.2996867 −2.109044 −0.330313 0 0.13 −2.3 −0.5 50.2996867 −2.109044 −0.330313 10 0.8111113 −1.532799 0.1811113 151.6715342 −0.560829 1.0415342 20 2.8936411 0.8253341 2.2636411 254.4965103 2.6540148 3.8665103 30 6.5071492 4.9663551 6.5071492 5.877149235 8.9627803 7.9627803 8.9627803 8.3327803 40 11.914111 10.91411111.914111 11.284111

TABLE 14 Lens Rx −2.0 Extension Power −0.50 Center Thickness 1 OpticDiameter 55 Edge Thickness 2.75 Spectacle Aperture 70 Base Curve 6.5Material: Polycarbonate B A2 A4 A6 A8 r D Front Optic 6.5 5.51E−031.67E−07 1.01E−11 7.69E−16 90.77 6.50 Extension 8.5 7.20E−03 3.74E−073.88E−11 5.03E−15 69.41 8.50 Frame 8 6.78E−03 3.12E−07 2.86E−11 3.29E−1573.75 8.00 Back Optic 8 6.78E−03 3.12E−07 2.86E−11 3.29E−15 73.75 8.00Sag Extension Front Back Frame R 8.00 6.5 8.5 8 −50 −45 −40 −35 −30 −253.5106816 5.6583626 4.3665103 −20 2.2301528 3.9437713 2.7636411 −202.230802 3.9437713 2.7636411 −15 1.247986 3.9437713 2.7636411 −100.5525291 1.724116 1.5415342 −5 0.1378165 1.180319 0.1696867 0 0 1 0 50.1378165 1.180319 0.1696867 10 0.5525291 1.724116 0.6811113 15 1.2479862.6401398 1.5415342 20 2.230802 3.9437713 2.7636411 25 3.51051033.5103816 3.6583626 4.3665103 30 5.5211492 5.4609142 7.8173879 6.377149235 7.9767803 7.9767803 10.467686 8.8327803 40 10.928111 10.92811113.674148 11.784111

TABLE 15 Lens radius 40.0 Front surface 3 number of polynomial piecesDegree of Polynomial Front surface (piece 1) 8 Degree of polynomialCoefficients of optically optimised central surface asphere applies fromr = 0 to r = 20 +0.00000D+00 0 +0.00000D+00 1 +1.03280D−02 2+0.00000D+00 3 +1.26810D−06 4 +0.00000D+00 5 +3.00100D−10 6 +0.00000D+007 +1.82900D−13 8 Blend radius (1-2) 20 Front surface (piece 2) 3 Degreeof polynomial Spline polynomial blending inner aspheric to outer sphereapplies from r = 20 to r = 35 −7.53462D+00 0 +8.36819D−01 1 −1.75540D−022 +2.72230D−4 3 Blend radius (2-3) 35 Front surface (piece 3) 8 Degreeof Polynomial Coefficients of outer sphere applies outside r = 35+2.10000D+00 0 +0.00000D+00 1 +7.43494D−03 2 +0.00000D+00 3 +4.10992D−074 +0.00000D+00 5 +4.54379D−11 6 +0.0000D+00 7 +6.27934D−15 8 Centrethickness 3.1 Back surface 1 number of polynomial pieces Back surface(piece 1) 8 Degree of Polynomial Coefficients of back surface sphere+3.10000D+00 +0.00000D+00 +7.54717D−03 +0.00000D+00 +4.29885D−07+0.00000D+00 +4.89723D−11 +0.00000D+00 +6.97363D−15 Radius Thickness sag(front) sag (back) zFront zBack TCrv  0.00 3.10 0.00 0.00 0.00 3.1010.95  1.00 3.10 0.01 0.01 0.01 3.11 10.95  2.00 3.09 0.04 0.03 0.043.13 10.95  3.00 3.07 0.09 0.07 0.09 3.17 10.96  4.00 3.06 0.17 0.120.17 3.22 10.96  5.00 3.03 0.26 0.19 0.26 3.29 10.97  6.00 3.00 0.370.27 0.37 3.37 10.99  7.00 2.96 0.51 0.37 0.51 3.47 11.00  8.00 2.920.67 0.48 0.67 3.58 11.02  9.00 2.87 0.85 0.61 0.85 3.71 11.03 10.002.81 1.05 0.76 1.05 3.86 11.05 11.00 2.75 1.27 0.92 1.27 4.02 11.0812.00 2.68 1.51 1.10 1.51 4.20 11.10 13.00 2.60 1.78 1.29 1.78 4.3911.13 14.00 2.52 2.08 1.50 2.08 4.60 11.17 15.00 2.43 2.39 1.72 2.394.82 11.20 16.00 2.33 2.73 1.96 2.73 5.06 11.24 17.00 2.22 3.10 2.223.10 5.32 11.29 18.00 2.10 3.49 2.49 3.49 5.59 11.34 19.00 1.97 3.912.78 3.91 5.88 11.39 20.00 1.83 4.36 3.09 4.36 6.19 −0.97 21.00 1.704.82 3.42 4.82 6.52 −0.32 22.00 1.58 5.28 3.76 5.28 6.86 0.33 23.00 1.485.74 4.12 5.74 7.22 0.98 24.00 1.40 6.20 4.50 6.20 7.60 1.62 25.00 1.336.67 4.90 6.67 8.00 2.25 26.00 1.27 7.14 5.31 7.14 8.41 2.87 27.00 1.237.62 5.75 7.62 8.85 3.47 28.00 1.20 8.11 6.21 8.11 9.31 4.06 29.00 1.178.61 6.68 8.61 9.78 4.62 30.00 1.16 9.12 7.18 9.12 10.28  5.15 31.001.15 9.65 7.70 9.65 10.80  5.65 32.00 1.15 10.19  8.24 10.19  11.34 6.12 33.00 1.15 10.75  8.80 10.75  11.90  6.55 34.00 1.16 11.32  9.3911.32  12.49  6.94 35.00 1.17 11.92  10.00  11.92  13.10  7.29 36.001.19 12.54  10.63  12.54  13.73  7.78 37.00 1.20 13.19  11.29  13.19 14.39  7.76 38.00 1.22 13.86  11.97  13.86  14.07  7.73 39.00 1.2314.55  12.68  14.55  15.78  7.70 40.00 1.25 15.28  13.42  15.28  16.52 7.67

TABLE 16 Lens radius 40.0 Front surface 3 number of polynomial piecesDegree of Polynomial Front surface (piece 1) 8 Degree of PolynomialCoefficients of optically optimised central surface asphere applies fromr = 0 to r = 20 +0.00000D+00 +0.00000D+00 +4.52750D−03 +0.00000D+00+1.17470D−07 +0.00000D+00 −7.92780D−11 +0.00000D+00 +1.86270D−14 Blendradius (1-2) 20 Front surface (piece 2) 3 Degree of Polynomial+1.44473D+01 −1.66106D+00 +6.22643D−02 −5.38318D−04 Blend radius (2-3)40 Front surface (piece 3) 8 Degree of Polynomial Coefficients ofoptically optimised central surface asphere applies from r = 0 to 4 = 20+0.00000D+00 +0.00000D+00 +7.43494D−03 +0.00000D+00 +4.10992D−07+0.00000D.00 +4.54379D−11 +0.00000D+00 +6.27934D−15 Centre thickness 1Back surface 1 number of polynomial pieces Backsurface (piece 1) 8Degree of Polynomial +1.00000D+00 +0.00000D+00 +7.54717D−03 +0.00000D+00+4.29885D−07 +0.00000D+00 +4.89723D−11 +0.00000D+00 +6.97363D−15 RadiusThickness sag (front) sag (back) zFront zBack TCrv  0.00 1.00 0.00 0.000.00 1.00 4.80  1.00 1.00 0.00 0.01 0.00 1.01 4.80  2.00 1.01 0.02 0.030.02 1.03 4.80  3.00 1.03 0.04 0.07 0.04 1.07 4.80  4.00 1.05 0.07 0.120.07 1.12 4.80  5.00 1.08 0.11 0.19 0.11 1.19 4.80  6.00 1.11 0.16 0.270.16 1.27 4.80  7.00 1.15 0.22 0.37 0.22 1.37 4.80  8.00 1.19 0.29 0.480.29 1.48 4.80  9.00 1.25 0.37 0.61 0.37 1.61 4.80 10.00 1.31 0.45 0.760.45 1.76 4.80 11.00 1.37 0.55 0.92 0.55 1.92 4.80 12.00 1.44 0.65 1.100.65 2.10 4.80 13.00 1.52 0.77 1.29 0.77 2.29 4.79 14.00 1.60 0.89 1.500.89 2.50 4.78 15.00 1.70 1.02 1.72 1.02 2.72 4.77 16.00 1.80 1.17 1.961.17 2.96 4.76 17.00 1.90 1.32 2.22 1.32 3.22 4.75 18.00 2.02 1.48 2.491.48 3.49 4.73 19.00 2.14 1.65 2.78 1.65 3.78 4.71 20.00 2.27 1.83 3.091.83 4.09 30.22  21.00 2.38 2.04 3.42 2.04 4.42 27.60  22.00 2.45 2.313.76 2.31 4.76 24.97  23.00 2.49 2.63 4.12 2.63 5.12 22.42  24.00 2.503.00 4.50 3.00 5.50 20.00  25.00 2.47 3.42 4.90 3.42 5.90 17.74  26.002.43 3.89 5.31 3.89 6.31 15.66  27.00 2.36 4.39 5.75 4.39 6.75 13.75 28.00 2.27 4.94 6.21 4.94 7.21 12.01  29.00 2.17 5.51 6.68 5.51 7.6810.42  30.00 2.06 6.12 7.18 6.12 8.18 8.97 31.00 1.95 6.75 7.70 6.758.70 7.65 32.00 1.83 7.41 8.24 7.41 9.24 6.43 33.00 1.71 8.09 8.80 8.099.80 5.30 34.00 1.60 8.79 9.39 8.79 10.39  4.25 35.00 1.49 9.50 10.00 9.50 11.00  3.26 36.00 1.40 10.23  10.63  10.23  11.63  2.31 37.00 1.3310.96  11.29  10.96  12.29  1.39 38.00 1.27 11.70  11.97  11.70  12.97 0.49 39.00 1.25 12.44  12.68  12.44  13.68  −0.40   40.00 1.25 13.18 13.42  13.18  14.42  −1.29  

Finally, it is to be understood that various other modifications and/oralterations may be made without departing from the spirit of the presentinvention as outlined herein.

What claimed is:
 1. An optical lens element including: a front and backsurface, at least one surface being continuous, and forming aprescription (Rx) zone and a non-prescription peripheral temporal zonefor providing a shield in the area of the temples, which zones aresmoothly blended to avoid a prismatic jump from the Rx zone to thetemporal zone.
 2. An optical lens element including: a front and backsurface, at least one surface being continuous, and forming aprescription (Rx) zone and a peripheral temporal zone for providing ashield in the area of the temples, which zones are smoothly blended toavoid a prismatic jump from the Rx zone to the temporal zone.
 3. Anoptical lens element according to claim 2, wherein the front and/or backsurfaces(s) of the optical lens element include a spherical or toriccomponent to provide the desired prescription (Rx) in the prescriptionzone.
 4. An optical lens element according to claim 3, wherein the lenselement is adapted for mounting in a frame of the wrap-around or shieldtype, such that the lens is rotated temporally about a vertical axisthrough the optical center thereof.
 5. An optical lens element accordingto claim 2, wherein the peripheral temporal zone is at least in part ofgenerally toric shape.
 6. An optical lens element according to claim 5,wherein the peripheral temporal zone is at least in part generallyplano.
 7. An optical lens element according to claim 6, wherein thecurvature of the front surface is modified in the peripheral temporalzone to substantially correspond to the curvature of the back surface.8. An optical lens element according to claim 2, wherein the lenselement is modified to permit light control within the peripheraltemporal zone.
 9. An optical lens element according to claim 8, whereinthe lens element includes one or more of the group consisting of amirror coating, a light control coating, a reflective coating or a lightcontrol tint within the peripheral temporal zone.
 10. An optical lenselement according to claim 2, wherein the shape of the front and/or backsurface in the region between the two zones is modified such that aprismatic jump from the Rx zone to the temporal zone is avoided.
 11. Anoptical lens element according to claim 10, wherein the shape of thefront or back surface in the region between the two zones is developedfrom a polynomial spline selected to smoothly blend the two zones. 12.An optical lense element according to claim 2 wherein the prescriptionzone extends beyond 50° off axis.
 13. An optical lens element accordingto claim 2, modified to accentuate facial form in the nasal region andincluding a region of reduced or opposite curvature defining a nasalaccentuating region.
 14. An optical lens element according to claim 2,wherein the lens element is an ophthalmic lens.
 15. An optical lenselement including a front and back surface providing prescription (Rx)correction zone in the range of about −6.0 to +6.0 D with about 0 to +3cyl and a peripheral temporal zone for providing a shield in the area ofthe temples, which zones are smoothly blended to avoid prismatic jumpfrom Rx zone to the temporal zone wherein the front surface is capableof being mounted in a frame of constant design curve irrespective of theRx, such frame curves being 5.0 D and above; and the back surfaceprovides good clearance from temples or eye lashes.
 16. An optical lenselement according to claim 15, wherein the lens element includes anon-prescription peripheral temporal zone.
 17. An optical lens elementaccording to claim 15, wherein the front surface is capable of beingmounted in a frame of constant design curve of between 8.0 D and 10.0 D.18. An optical lens element according to claim 15, wherein the frontsurface of the lens element has a high curve extending from nasal totemporal limits, but the vertical curve is 8.0 D or below.
 19. Anoptical lens element according to claim 16, wherein the shape of thefront and/or back surface in the region between the two zones ismodified such that a prismatic jump from the Rx zone to the temporalzone is avoided.
 20. An optical lens element according to claim 19,wherein the shape of the front or back surface in the region between thetwo zones is developed from a polynomial spline selected to smoothlyblend the two zones.
 21. An optical lens element according to claim 15,wherein the prescription zone extends beyond 50° off axis and optionallyterminates in a peripheral temporal zone.
 22. A unitary lens including apair of optical lens elements, each lens element including a front andback surface, at least one surface being continuous, and forming aprescription (Rx) zone and optionally a peripheral temporal zone forproviding a shield in the area of the temples, which zones are smoothlyblended to avoid a prismatic jump from the Rx zone to the temporal zone;and providing prescription (Rx) correction in the range of about −6.00 Dto +6.00 D with about 0 to +3 cyl wherein the front surface is capableof being mounted in a frame of constant design curve irrespective of theRx, such frame curves being 5.0 D and above; and the back surfaceprovides good clearance from temples or eye lashes.
 23. A unitary lensaccording to claim 22, wherein the peripheral temporal zone is anon-prescription zone.
 24. A unitary lens according to claim 23 whereinthe lens provides true Rx correction in the prescription (Rx) zone for awearer not greater than 50° off axis.
 25. A unitary lens according toclaim 22, wherein the lens provides true Rx correction in theprescription (Rx) zone for a wearer extends beyond 50° off axis andoptionally terminating in a peripheral temporal zone, that providesclear perception of objects in the peripheral area of human vision andavoids prismatic jump from the prescription zone to the peripheraltemporal zone.
 26. A unitary lens according to claim 25, wherein theprescription zone extends up to 80° off axis.
 27. An optical lenselement according to claim 22, wherein the shape of the front and/orback surface in the region between the two zones is modified such that aprismatic jump from the Rx zone to the temporal zone is avoided.
 28. Anoptical lens element according to claim 27, wherein the shape of thefront or back surface in the region between the two zones is developedfrom a polynomial spline selected to smoothly blend the two zones. 29.An optical lens element adapted for mounting in a frame of thewrap-around or shield type, such that the lens element is rotatedtemporally about a vertical axis through the optical center thereof, thelens element including a front and back surface, at least one surfacebeing continuous and forming a prescription (Rx) zone with non-zerothrough power; wherein at least one of the front and back surfaces bearsa surface correction to at least partially adjust for rotationallyinduced errors including astigmatic and mean power errors throughout theprescription zone.
 30. An optical lens element according to claim 29,wherein at least one of the front and back surfaces further includes asurface correction to at least partially adjust for prismatic errors.31. An optical lens element according to claim 30, wherein at least oneof the front and back surfaces includes a toric component and bears asurface correction to at least partially adjust for on-axis astigmaticand mean power errors.
 32. An optical lens element according to claim31, wherein at least one of the front and back surfaces includes anaspheric component selected to at least partially adjust for off-axisastigmatic and mean power errors.
 33. An optical lens element accordingto claim 32, wherein the front surface is an aspheric surface thatincludes appropriate aspheric coefficients to define a peripheraltemporal zone.
 34. An optical lens element according to claim 33,wherein the aspheric front surface exhibits line symmetry about thehorizontal geometric axis thereof.
 35. An optical lens element accordingto claim 34, wherein the aspheric surface exhibits line symmetry aboutthe vertical geometric axis thereof.
 36. An optical lens elementaccording to claim 33, wherein the aspheric surface includes acorrection in the horizontal direction.
 37. An optical lens elementaccording to claim 29, wherein the optical axis is decentered relativeto the geometric axis of the lens element.
 38. An optical lens elementaccording to claim 37, wherein the optical axis is decentered verticallyrelative to the geometric axis of the lens element to at least partiallycompensate for pantoscopic tilt.
 39. An optical lens element accordingto claim 37, wherein the optical axis is decentered horizontallyrelative to the geometric axis of the lens element to provide forprismatic correction.
 40. An optical lens element according to claim 29,wherein the lens provides true Rx correction in the prescription (Rx)zone for a wearer not greater than 50° off axis.
 41. An optical lenselement according to claim 29, wherein the lens provides true Rxcorrection in the prescription (Rx) zone for a wearer which extendsbeyond 50° off axis and terminates in a peripheral temporal zone, thatprovides clear perception of objects in the peripheral area of humanvision and avoids prismatic jump from the prescription zone to theperipheral temporal zone.
 42. An optical lens element according to claim29, wherein the back surface includes a base curvature such that thepatient's required prescription power, Rx, in the prescription zone isachieved; the back surface being further modified to complement thefront surface selected.
 43. An optical lens element according to claim42, wherein the back surface includes a toric or spherical componentselected to achieve the prescribed optical power and the prescriptionlens cylinder correction.
 44. An optical lens element according to claim43, wherein the back surface further includes an astigmatic errorcorrection to compensate for lens wrap.
 45. An optical lens elementaccording to claim 44, wherein the surface is an aspheric toric surfaceand includes an adjustment to correct for off-axis astigmatic and/ormean power errors.
 46. An optical lens element according to claim 29,including an aspheric front surface that includes a base curvatureappropriate for high base curve lenses and appropriate asphericcoefficients to define a peripheral temporal zone; and a back surface ofappropriate curvature to provide the prescribed optical lens power andprescribed lens cylinder and including adjustments for astigmatic andmean power error correction to compensate for lens wrap.
 47. An opticallens element according to claim 46, wherein the back surface includes atoric or spherical component.
 48. An optical lens element according toclaim 46, including a front surface including a spherical or toriccomponent designed to provide the desired prescription (Rx) in theprescription zone, and bearing a surface correction to at leastpartially adjust for errors including astigmatic and mean power errors,in combination with the back surface, and including appropriatecoefficients to define a peripheral temporal zone; and a transitionsection therebetween designed to smoothly blend the prescription zoneand peripheral temporal zone, and a back surface modified to complementthe front surface.
 49. The optical lens element of claim 29, furthercomprising a peripheral temporal zone.
 50. The optical lens element ofclaim 29, incorporated into eyewear wherein the vertical axis ofrotation corresponds to the meridional axis of the lens element as wornand the lens element is rotated temporally with respect to a normal lineof sight.
 51. The article of claim 50 wherein at least one of therotationally induced astigmatic error and mean power error is onlypartially corrected on the normal line of sight of the lens element inthe as worn position.
 52. The article of claim 50 wherein bothrotationally induced astigmatic error and mean power error are onlypartially corrected on the normal line of sight in the as worn positionand partially corrected temporally and nasally away from the normal lineof sight in the prescription zone.
 53. An optical lens element adaptedfor mounting in a frame of the wrap-around or shield type, the lenselement including a front and back surface, at least one surface beingcontinuous, the surfaces forming a prescription (Rx) zone with non-zerothrough power; wherein the optical axis is decentered relative to thegeometric axis of the lens element, at least one of the front and backsurfaces bearing a surface correction to at least partially adjust foroff-axis errors including astigmatic and mean power errors throughoutthe prescription zone.
 54. An optical lens element according to claim53, wherein the optical axis is decentered vertically relative to thegeometric axis of the lens element to at least partially compensate forpantoscopic tilt.
 55. An optical lens element according to claim 53,wherein the optical axis is decentered horizontally relative to thegeometric axis of the lens element to provide for prismatic correction.56. An optical lens according to claim 53, wherein the lens elementincludes a non-prescription peripheral temporal zone.
 57. An opticallens element according to claim 53, wherein the lens element is rotatedtemporally about a vertical axis through the optical center thereof whenmounted in eyewear.
 58. An optical lens element according to claim 57,wherein at least one of the front and back surfaces further includes asurface correction to at least partially adjust for off-axis astigmaticand mean power errors as well as to avoid prismatic jump.
 59. Anophthalmic lens including a front and back surface, at least one surfacebeing continuous, and forming a prescription (Rx) zone and a peripheraltemporal zone for providing a shield in the area of the temples, whichzones are smoothly blended to avoid a prismatic jump from the Rx zone tothe temporal zone.
 60. An optical lens element incorporated intowrap-around eyewear such that the lens element is rotated temporallyabout an axis through the optical center thereof, said axis beingvertical in the as worn position and said temporal rotation being arotation of the lens element with respect to the normal line of sight,the lens element including a front and back surface, at least onesurface being continuous, the surfaces forming a prescription (Rx) zonewith non-zero through power; at least one of the front and back surfacesbearing a surface correction to at least partially adjust forrotationally induced errors including astigmatic and mean power errorsaway from the normal line of sight both temporally and nasally.
 61. Anoptical lens element adapted for mounting in a frame of the wrap-aroundor shield type, the lens element including a front and back surface, atleast one surface being continuous, the surfaces forming a prescription(Rx) zone with non-zero through power; wherein the optical axis isdecentered relative to the geometric axis of the lens element, at leastone of the front and back surfaces bearing a surface correction to atleast partially adjust for off-axis errors including astigmatic and meanpower errors throughout the prescription zone.
 62. An optical lenselement according to claim 61, wherein the optical axis is decenteredvertically relative to the geometric axis of the lens element to atleast partially compensate for pantoscopic tilt.
 63. An optical lenselement according to claim 61, wherein the optical axis is decenteredhorizontally relative to the geometric axis of the lens element toprovide for prismatic correction.
 64. An optical lens element accordingto claim 61, wherein the lens element provides true Rx correction in theprescription (Rx) zone for a wearer not greater than 50° off axis. 65.An optical lens element according to claim 61, wherein the lens elementprovides true Rx correction in the prescription (Rx) zone for a wearerextends beyond 50° off axis.
 66. The optical lens element of claim 61,further comprising a peripheral temporal zone.